Ankle fracture with both deltoid ligament (DL) rupture and syndesmotic diastasis is often treated by syndesmotic fixation after fibular fixation. However, a second operation may be needed to remove the internal fixation, and screw breakage/misplacement may occur. The present study aimed to explore the mechanism and feasibility of DL augmentation instead of syndesmotic fixation from the perspective of biomechanics. The CT data (in DICOM format) of a 33-year-old man were used to create a finite element model. External rotation stress and eversion stress were applied to the model, and the medial clear space (MCS) and tibiofibular clear space (TCS) were evaluated. In a separate experiment, preserved lower limb specimens were fixed on a hydraulic loading frame before undergoing DL augmentation and syndesmotic fixation in random order. A mechanical testing device was used to apply external rotation stress (4 N·m) and eversion stress (2.5 N·m) to the two groups (DL augmentation or syndesmotic fixation). The MCS and TCS were measured and compared between the two groups. In the finite element study, the MCS widening was lesser and the TCS widening was greater in the DL augmentation group than in the syndesmotic fixation group in both the external rotation and eversion tests. Nine specimens were analyzed in the biomechanical tests. There were no significant differences between the two groups in the widening of the TCS in the rotation tests (p = 0.093, Hodges-Lehmann median difference = -0.79, 95% confident interval: -1.70~0.27) and eversion tests (p = 0.237, HLD = -0.84, 95% CI: -2.57~1.09). However, the widening of the MCS was significantly lesser in the DL augmentation group than in the syndesmotic fixation group during the rotation tests (p = 0.036, HLD = 3.57, 95% CI: 0.40~6.41) and eversion tests (p = 0.018, HLD = 4.36, 95% CI: 1.84~7.35). Compared with syndesmotic fixation, DL augmentation has better resistance to medial malleolar space widening under both external rotation and eversion forces and can restore the tibiofibular space to a certain extent. These results suggest that DL augmentation alone is a potential alternative to syndesmotic fixation for Weber-type C ankle fractures from a biomechanical point of view.

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, for example in length-unstable syndesmotic injuries. The aim of this biomechanical study was to investigate whether a novel screw-suture implant addresses such issues compared to suture-button implants while preserving dynamic capabilities. Eight pairs of human cadaveric lower legs were injured by complete syndesmosis and deltoid ligaments cuts, and reconstructed using a screw-suture (FIBULINK, Group 1) or a suture-button (TightRope, Group 2) implant for syndesmotic stabilization, placed 20mm proximal to the tibia plafond. Following, all specimens were biomechanically tested over 5000 cycles under combined 1400N axial and ± 15° torsional loading. Anteroposterior, axial/vertical, mediolateral and torsional movements at the distal tibiofibular joint level were evaluated biomechanically via optical motion tracking. Anteroposterior and axial/vertical movements were significantly smaller and maintained over the cycles in Group 1 compared with Group 2 (p < 0.001). No further significant differences were identified between the groups (p ≥ 0.318). Although both implant systems demonstrate ability for stabilization of unstable syndesmotic injuries, the screw-suture reconstruction provides better anteroposterior and axial/vertical stability of the distal tibiofibular joint, and maintains it over time under dynamic loading in a cadaveric study design. Therefore, it could be considered as a valid option for treatment of syndesmotic disruptions with length-unstable fibula. Level V, Controlled Laboratory Study.

Arthroscopic Approach to Deltoid Injuries.

Rationale:A comminuted fracture of the medial malleolus combined with a talar neck fracture is a uncommon finding. Surgeons are often unaware of its unique injury mechanism, which complicates fracture reduction and fixation and may cause potential complications during and after surgery. This report presents a case of a talar neck fracture combined with a comminuted medial malleolar fracture and analyzes its injury mechanism.Patient concerns:A 35-year-old Chinese man sustained a talar neck fracture and comminuted medial malleolus in an electric bicycle accident, accompanied by inability to bear weight.Diagnoses:Radiographs and computed tomography confirmed a displaced talar neck fracture with intra-articular extension and a comminuted medial malleolar fracture. magnetic resonance imaging additionally revealed deltoid ligament rupture and tibialis posterior tendon exposure.Interventions:After 5 days of skin swelling resolution, he underwent open reduction and internal fixation using compression screws, Kirschner wires, and transosseous tunnel sutures.Outcomes:At the 10-month follow-up, radiographs showed satisfactory bone healing without avascular necrosis. Functional outcome improved significantly, with the American orthopaedic foot & ankle society ankle-hindfoot score rising from 20 preoperatively to 85 at final assessment.Lessons:This case supports pronation-dorsiflexion as the likely injury mechanism. Recognition of concomitant ligament and tendon injuries is critical. Combined screw fixation and transosseous tunnel sutures can achieve stable fixation, preserve ankle joint function, and reduce the risk of complications.

Background: While gravity-assisted ankle stress AP (GAASA) images have proven effective in evaluating deep deltoid ligament injuries, their efficacy in assessing syndesmosis injuries remains unclear. We aimed to investigate the diagnostic performance of GAASA images in detecting syndesmosis injuries. Methods: This study reviewed records of patients aged 16+ with unilateral ankle fractures in a single-center ER from 2022 to 2023. Three orthopedic surgeons evaluated standard AP and lateral X-rays, ankle mortise, and GAASA and bilateral ankle CT images in blinded sessions for syndesmosis injuries. Evaluations were repeated to assess the inter- and intra-rater reliability. Results: A total of 121 patients with suspected syndesmosis injuries were included in this study. The average age of the patients was 49.9 ± 16.6 years. Syndesmosis injuries were present in 32.2% of cases. The inter-observer reliability was the highest for GAASA images (κ = 0.701) and mortise radiographs (κ = 0.735), and lowest for CT images (κ = 0.426). GAASA images had a sensitivity of 82% and specificity of 68%. Mortise images had 55% sensitivity and 81% specificity. GAASA images showed better discriminatory power for syndesmosis injuries compared to mortise and CT images. Conclusions: GAASA images demonstrated superior sensitivity and better negative predictive values in detecting syndesmosis injuries compared to mortise radiographs and CT images. While GAASA may serve as a useful adjunct for evaluating syndesmosis injuries, its interpretation requires careful clinical correlation, and it should not be considered a replacement for standard imaging in all cases. GAASA may be of particular value in emergency or resource-limited settings where CT is not readily available, offering a practical option for ruling out injury in many patients.

Medial column nails have been introduced into Charcot's neuroarthropathy reconstruction as superconstruct fixation with high fatigue strength and pullout resistance. Similar to intramedullary nailing throughout other long-bone fixation, injury to neurovascular and musculotendinous structures secondary to percutaneous interlocking screw fixation may exist. We sought to identify structures at risk for injury during the interlocking of a medial column nail. Medial column nails were inserted into ten cadaveric limbs. The proximal (talar), middle (first metatarsal), and distal (first metatarsal) locations for the interlocking screws were drilled, and a 0.062 Kirschner wire was inserted into respective drillholes to simulate interlocking screws. After dissection, the distances of each Kirschner wire to nearby anatomical structures were measured. Levels of risk were assigned to each soft-tissue structure based on distance to each Kirschner wire: high (0-3.5 mm), intermediate (3.6-7.0 mm), and low (>7.0 mm). A 3.5-mm threshold for each category was used because this represented a multiple of the diameter of the interlocking screws. Mean ± SD and ranges are reported for structures at high and intermediate risk for injury. Proximally, the deltoid ligament (ten of ten), posterior tibial tendon (eight of ten), and saphenous vein (six of ten) were at high or intermediate risk for injury consistently. At the middle screw, the medial dorsal cutaneous nerve and the medial marginal vein were at high or intermediate risk in ten and eight specimens, respectively. At the distal interlocking screw, the medial dorsal cutaneous nerve was at high risk for injury in all ten specimens. There is high and intermediate risk to many musculotendinous and neurovascular structures when performing percutaneous interlocking screws in a medial column nail. These findings serve to educate surgeons of the anatomical considerations they must have when performing medial column nailing for reconstruction of Charcot's foot.

Association Between Isolated Fibular Fracture Displacement and Deep Deltoid Injury: A Comparative Analysis of Arthroscopic and Radiographic Assessments.

The utility of needle arthroscopy in the ankle joint: A cadaveric study evaluating visualization, surgical feasibility, and learning curve considerations.

The goal of this Acta Orthopaedica educational article is to provide an update on how to evaluate lateral malleolar ankle fractures at the level of the syndesmosis and to guide clinicians in selecting the most appropriate treatment method. We aim to clarify the indications for non-surgical treatment and to provide clinicians with an evidence-based approach to decision-making in these frequently encountered injuries. The authors introduce the concept of “congruent on weightbearing” in contrast to the historical thinking of ankle fractures as stable or unstable. We further elaborate on how this thinking should be the basis in the decision-making regarding treatment method to safely differentiate fractures that will heal uneventfully without surgical intervention from those that need internal reduction and stabilization.As long as crucial parts of the deltoid ligament are intact, lateral malleolar ankle fractures at the level of the syndesmosis maintain, or regain, joint congruency under weightbearing. Ankle fractures that stay congruent under weightbearing often heal uneventfully and can be safely treated without surgery. Furthermore, research has shown that early weightbearing and short immobilization periods are beneficial for patient recovery without an increase in complication rates.

Research Type: Level 2 - Prospective comparative study, Meta-analysis of Level 2 studies or Level 1 studies with inconsistent results Introduction/Purpose: Ankle fractures are among the most common orthopedic injuries and are frequent associated to deltoid ligament. Despite the high prevalence of this injury, there is still no consensus on the need for repair of the deltoid ligament. However, it is increasingly believed that, due to its role in rotational instability, repair should be performed in all cases. The use of arthroscopy associated with the treatment of ankle fractures allows the identification of associated injuries allows removing debris and proteases that can accelerate the process of joint degeneration. Arthroscopic deltoid ligament repair has been demonstrating results like open repair, with less local morbidity. This study aims to functionally evaluate patients undergoing surgical deltoid ligament repair and compare the currently available methods. Methods: A prospective observational study was conducted to monitor outcomes. Inclusion criteria included all patients over 18 years of age undergoing surgical treatment for ankle fractures, provided they had no prior surgeries on the affected ankle. Exclusion criteria included patients with chronic joint diseases, previous surgeries on the affected ankle, those unwilling to participate in the study, or those without the cognitive capacity to consent. All patients with surgical ankle fractures were approached arthroscopically, and the pattern of their ligament injuries was documented. The OMAS scale was applied to all participants after a minimum follow-up of two years, with data collected via telephone survey. Results: A study of 121 patients included 53 women (43.8%) and 68 men (56.2%). Regarding deltoid ligament injuries, 77 patients had no injury (63.6%), while 44 patients (36.4%) presented with deltoid ligament injury. Among the patients with deltoid injury, 33 cases (75.0%) were repaired; of these, 10 underwent open repair and 23 underwent arthroscopic repair. Tourniquet time was longer in cases where the deltoid ligament was repaired (p = 0.0068; 95% CI −35.34,−6.52). Functional outcomes measured by the OMAS scale showed an average score of 88 in patients without deltoid injury, 80 in patients with deltoid injury not requiring repair, 75 in those who underwent open deltoid repair, and 78 in those who underwent arthroscopic repair, indicating similar functional results between the two repair methods. Conclusion: This study helps surgeons in the decision-making process when treating ankle fractures with deltoid ligament injuries. By identifying clear injury patterns, it allows a more specific and individualized approach to treatment. The results also confirm that arthroscopic repair of the deltoid ligament is a safe and reliable method, providing functional outcomes similar to open repair, with the advantage of less local morbidity. These findings encourage the use of arthroscopy as an effective option for managing these injuries.

Research Type: Level 5 - Case report, Expert opinion, Personal observation Introduction/Purpose: Sagittal plane alignment has become increasingly important for evaluating syndesmotic reduction in ankle fractures. Traditional parameters including tibiofibular overlap/clear space have limitations. Intraoperative CT or arthroscopy are not universally accessible. Consequently, reliance often remains on lateral fluoroscopic imaging. There is an increasing reliance as previous investigations confirm that sagittal tibiofibular alignment can reliably assess syndesmotic reduction. However, ankle fractures are often associated with concomitant medial and/or lateral ligamentous injuries which may alter talar positioning and affect measurements, even if the syndesmosis is intact and may result in apparent syndesmotic malalignment. This study used a cadaveric model to determine the impact of sequentially sectioning these ligaments on sagittal tibiofibular alignment and hypothesized that progressive ligament destabilization would change the apparent radiographic syndesmotic alignment. Methods: Twelve knee disarticulated cadaveric lower leg specimens, each with an intact syndesmosis, were mounted in neutral position. Lateral ankle fluoroscopic images were obtained with a C-arm ensuring a true lateral view by confirming talar dome superimposition. Baseline tibiofibular alignment measurements—specifically, the fibula-tibial interval ratio, anterior-posterior fibular translation, and fibular plafond coverage—were recorded. Then sequential ligament sectioning followed this order: (1) superficial deltoid ligament, (2) deep deltoid ligament, and (3) anterior talofibular ligament (ATFL). After each cut, the specimen was repositioned to recapture a true lateral radiograph and the tibiofibular alignment measurements were repeated. Results: In the intact condition, the mean PTFI/(PTFI+FW) ratio was 0.245, which rose to 0.323 following deltoid ligament sectioning. After subsequent ATFL sectioning, the ratio was 0.292, demonstrating that most of the increase in tibiofibular overlap occurred after medial-sided (deltoid) disruption. Additional sectioning of the ATFL had only a minimal effect on sagittal tibiofibular measurements. Neither anterior-posterior fibular translation (AD measure) nor fibular plafond coverage showed statistically significant differences across the three conditions. These data suggest that the deltoid ligament incompetence can create the impression of syndesmotic malalignment even when the syndesmosis remains anatomically intact. Ongoing analysis will further clarify the influence of isolated lateral ligament disruption, though early results indicate its overall impact is significantly smaller than that of deltoid insufficiency. Conclusion: While there is an increased reliance on sagittal plane alignment to assess syndesmotic malreduction, the effects of ligament disruption are unknown. Sequential sectioning of medial and lateral ligaments altered tibiofibular alignment on sagittal radiographs in cadaveric models resulting in apparent syndesmotic malalignment despite intact syndesmotic ligaments. Notably, deltoid ligament disruption produced the greatest change, indicating that medial-sided ligamentous incompetence alone can alter lateral radiographic assessments of syndesmotic reduction. Surgeons should remain cognizant that an intact syndesmosis may appear malaligned on lateral imaging when deltoid integrity is compromised.

Background:Suturing the deep posterior deltoid ligament in unstable ankle fractures is novel to established treatment. Some cadaveric and clinical trials support that adding deltoid ligament repair to plating of the lateral fracture will improve stability restoration.Objectives:We will investigate the effects of deep deltoid ligament repair on patient-reported function, radiologic stability parameters, and the incidence of ankle osteoarthritis and the possible side effects from this additional procedure. The medial ankle injury patterns found will be described.Study design:A randomised controlled nonblinded multicentre trial.Methods:A total of 120 patients with Lauge Hansen SER 4B ankle fractures will be randomised (1:1 ratio) to conventional plating of the lateral malleolus only or additional suture of the deep deltoid ligament. The primary end point was patient-reported function measured in Olerud-Molander Ankle Score (OMAS) at 1 and 2 years. The secondary end points included Self-Reported Foot and Ankle Score (SEFAS), Ankle Fracture Outcome of Rehabilitation Measure (A-FORM), VAS pain, and EuroQol-5D-5L scores; rates of treatment-related adverse events, reoperations, and incidence of posttraumatic arthritis; and comparison of side-to-side differences in tibiotalar medial clear space from bilateral weightbearing ankle radiographs and gravity stress on group level.

Deltoid ligament insufficiency in hindfoot arthrodesis for progressive collapsing foot deformity: A retrospective analysis.

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: The deltoid ligament provides crucial stability and support to the ankle joint, especially against valgus stress. 20-58% of ankle fractures occur with concomitant deltoid ruptures. The role of deltoid repair (DR) in ankle fracture surgery remains controversial, as mixed data exist on to what extent DR improves patient-reported outcomes and reduces complication rates. This study aims to determine whether DR reduces complications and improves outcomes measured by Patient Reported Outcomes Measurement Information System (PROMIS) computerized adaptive tests (CATs) of physical function (PF) and pain interference (PI). We hypothesized that DR would reduce complications and improve PROMIS scores. Methods: This was a retrospective study of 782 patients at a single institution who underwent ankle fracture surgery between January 2016-December 2021. Two fellowship-trained foot and ankle orthopaedic surgeons independently reviewed all radiographs and assessed reduction quality and complications at final follow-up. Multiple extremity injuries, open fractures, and pilon variants were excluded. Deltoid ligament rupture was radiographically identified by injury films, defined as a ≥2mm difference between the superior clear space and the medial clear space, or stress positive with same criteria. 345 patients with deltoid ruptures were sent PROMIS CATs. 265 patients with minimum one-year follow-up were analyzed for complications. 112 patients who completed CATs were analyzed for PROMIS. A subgroup analysis with only the 83/112 isolated fibular fractures was also conducted. Wilcoxon rank-sum test compared PROMIS between groups. Linear regression modeled DR effect on PROMIS adjusted for relevant covariates and propensity scores. Results: 50/265 (18.9%) underwent DR. Radiographic complication incidence among 215 patients (81.1%) without repair (DNR) was 14.42%: 7 (3.26%) degenerative joint disease, 3 (1.40%) ankle joint malreduction, 4 (1.86%) syndesmotic malreduction, and 8 (3.72%) malleolar malunion. DR had no radiographic complications. Among patients who completed CATs (n=112), DR (n=21) had non-significantly higher mean PF (54.31±9.83 vs. 52.79±10.42, P=.71) and non-significantly lower mean PI (47.21±7.82 vs. 48.53±8.37, P=.59). Adjusted regression models estimated 1.89-point increase in PF and 1.67 decrease in PI for DR vs. DNR. When adjusted for propensity scores, DR had PF 2.17 higher and PI 1.73 lower vs. DNR. Among isolated fibular fractures, DR had PF 2.28 higher and PI 1.04 lower and PF 2.32 higher and PI 0.96 lower when adjusting for propensity scores. Conclusion: DR reduces complications, notably syndesmotic malreduction and degenerative joint disease, following ankle fracture surgery regardless of fracture subtype, likely due to improved ankle joint stability and alignment. While this study was underpowered to detect small effect sizes in PROMIS, modest improvements in functional outcomes suggest DR may improve patient-reported outcomes. Future studies with larger samples are ultimately needed to determine definitively whether repair improves outcomes as measured by PROMIS.

Research Type: Level 5 - Case report, Expert opinion, Personal observation Introduction/Purpose: Deltoid ligament injuries occur in predefined sequences during rotational ankle fractures, but current knowledge about these sequences may be inaccurate. Computer modeling provides a novel approach to evaluate ligament behavior under rotational injury mechanisms. Methods: A biomechanical computer simulation model was developed using the AnyBody Modeling Software to evaluate ligament strain in rotational ankle injuries. Experimental data from a cadaveric study involving 18 human ankle specimens subjected to various loading conditions were used to optimize the computer model. Having optimized the computer model with uninjured cadaveric data, we simulated Supination-External Rotation (SER) stage 2-4b injuries by removing corresponding ligaments. Validation was done by comparing computer model predictions against the biomechanical experimental data. Results: The computer model replicated experimental findings, with correlation coefficients ranging from 0.81 to 0.99 across all injury stages and loading conditions. Furthermore, tension in the deep posterior tibiotalar ligament (DPTTL) increased progressively from SER2 to SER4a but remained unchanged in the SER2 phase. The model successfully captured progressive ligament strain and medial clear space changes during injury progression. Conclusion: This study introduces and validates a biomechanical simulation model for rotational ankle injuries. It offers a novel tool for exploring ligament biomechanics and injury mechanisms. The medial sagittal view of the computer model with the ligaments specified. Deltoid ligament sections are shown with black arrows, while other ligaments are shown with blue arrows. The deep deltoid sections are also shown with solid arrows and depicted as red. Note that the tibiofibular syndesmosis ligaments were hidden for the sake of visibility.

Research Type:Level 5 - Case report, Expert opinion, Personal observationIntroduction/Purpose:Syndesmotic malreduction is a well-documented problem negatively impacting outcomes with a reported incidence approaching 52%. Screw placement between 1.5 – 6 cm above the tibial plafond has been traditionally advocated. Despite this, the optimal height for screw fixation remains unclear and its potential effects on syndesmotic malreduction unknown. As more proximal placement would theoretically lead to increased syndesmotic malreduction given increased distance from the osseous constraints of the incisura, screw height placement may be a modifiable variable to improve syndesmotic reduction. This cadaveric study employed weightbearing computed tomography (WBCT) to evaluate the effects of screw fixation height on syndesmotic alignment in a simulated pronation-external rotation (PER) ankle fracture model. We hypothesized that increasing screw fixation height correlates with a higher degree of syndesmotic malreduction.Methods:Twelve knee-disarticulated, cadaveric specimens underwent simulated PER ankle fracture injuries with disruption of the deep deltoid ligament, syndesmosis and creation of a proximal fibula fracture. A 1/3 tubular plate was affixed to the distal fibula with screw fixation placed incrementally from 1.5 cm to 6.5 cm above the tibial plafond. Four fellowship-trained orthopaedic surgeons performed all trials and manually reduced the syndesmoses by direct thumb-reduction followed by fixation using a fully threaded quad-cortical metal screw under fluoroscopic guidance. WBCT imaging was performed post-fixation after each trial at each screw fixation height to assess syndesmotic alignment, screw angulation, and incisural morphology. WBCT imaging were analyzed utilizing both traditional 2-D measurements (distance, area) and advanced 3-D volumetric analyses.Results:Syndesmotic diastasis measurements varied with screw fixation height (p = 0.035 for posterior diastasis, p < 0.0001 for mid-diastasis, and p = 0.023 for anterior diastasis). Fibular rotation and translation also demonstrated significant differences depending on height (p < 0.001). Syndesmotic volume analyses showed no significant differences between fixation levels (p = 0.054) indicating no effect of screw fixation height on total volumes. However, more proximal screw fixation levels increased total volumes and resulted in distal widening supporting a “see saw” effect of more proximal fixation. While no screw fixation level fully restored pre-sectioned syndesmotic alignment, a screw placed 27mm above the tibial plafond lead to measurements closest to the intact state on both 2-D and 3-D analyses. Incisural morphology did not affect syndesmotic measurements.Conclusion:This study confirms that screw fixation height influences syndesmotic reduction with increasing distance from the tibial plafond increasing volume and altering diastasis measurements. A “see saw” effect was evident as more proximal fixation lead to distal syndesmotic widening. While no screw level perfectly restored normal syndesmotic alignment, a screw placed 27mm above the tibial plafond resulted in measurements closest to native pre-injury syndesmotic alignment and appears optimal for minimizing malreduction risks.

Research Type:Level 2 - Prospective comparative study, Meta-analysis of Level 2 studies or Level 1 studies with inconsistent resultsIntroduction/Purpose:According to Lauge-Hanse, suprasyndesmotic ankle fractures occur in pronation type injuries to the ankle. Because of the expected instability of these fractures, operative stabilization is advised. Recent studies on Weber B fractures have shown that varying degrees of medial injury exist, influencing stability and treatment approach. The deep posterior part of the deltoid complex has been found to play a crucial role in maintaining talocrural stability. A congruent ankle joint on stress radiographs may indicate intact medial stability, suggesting that operative stabilization may not be warranted. However, studies on the ligamentous injuries of suprasyndesmotic ankle fractures that show congruency on weightbearing radiographs are lacking. This study aims to utilize MRI to examine the ligamentous injuries in suprasyndesmotic ankle fractures that appear stable on stress radiographs.Methods:Twenty patients with suprasyndesmotic ankle fractures (Weber C/Maisonneuve) and talocrural congruency on weightbearing radiographs were recruited from Oslo University Hospital and Østfold Hospital, Kalnes. MRI was performed within two weeks of the injury. Two senior musculoskeletal radiologists from both centres assessed the images and scored the ligamentous injuries to the deltoid ligaments and syndesmotic ligaments based on the degree of damage (intact, partial, or complete rupture). In cases of disagreement between radiologists on the degree of damage, a consensus would be reached.Results:We included twenty patients during a period of one year (2023-2024). Mean age was 55 years (22-75). High fibular fractures (Maisonneuve) accounted for 55% of the included injuries. The anterior inferior tibiofibular ligament (AITFL) and intraosseous ligament (IOL) was completely ruptured in 90% (18/20). The posterior inferior tibiofibular ligament (PITFL) and the deep posterior tibiotalar ligament (dPTTL) was completely ruptured in only 10% (2/20).Conclusion:Suprasyndesmotic ankle fractures that show talocrural congruency on weightbearing radiographs tend to have an intact deep posterior tibiotalar ligament and posterior inferior tibiofibular ligament when assessed by MRI. These fractures may retain sufficient stability to be managed conservatively in line with the current approach to stable Weber B fractures, but further clinical studies are needed.

Research Type: Level 4 – Case series Introduction/Purpose: Weber B fractures often show unstable gravity stress tests but stable weightbearing radiographs (classified SER4a), suggesting partial deltoid ligament injury with an intact deep posterior tibiotalar ligament (dPTTL). Conversely, a dPTTL rupture is assumed if both radiographs are unstable (classified SER4b). However, the state of the dPTTL in SER4a vs. SER4b has not been well studied. This study assessed the prevalence of dPTTL injury using direct visualization during arthroscopy of SER4a and SER4b fractures. Methods: We conducted a prospective study on 20 patients with Weber B/SER4a-b ankle fractures having unstable gravity stress tests or unstable weightbearing radiographs (medial clear space ≥ 4.0 millimeters). Blinded assessors evaluated the dPTTL using minimally invasive arthroscopy under local anesthesia. Intact dPTTL was defined by normal ligament visualization with tensioning and medial joint space closing with dorsiflexion. Results: Based on radiographic criteria, 15 patients were classified as SER4a and five as SER4b. Arthroscopy showed an intact dPTTL in 14 SER4a injuries. One patient with a 3.9 mm medial clear space had a torn dPTTL. All SER4b injuries revealed dPTTL disruptions with arthroscopic assessment. Conclusion: In Weber B fractures evaluated arthroscopically, the dPTTL is typically intact in cases where weightbearing radiographs are stable despite unstable gravity stress tests. Conversely, complete dPTTL disruption was consistently observed in cases where both tests were unstable. These findings support the hypothesis that a stable weightbearing radiograph indicates an intact dPTTL.

Research Type: Level 4 – Case series Introduction/Purpose: Adult-acquired flatfoot deformity (AAFD) can occur due to posterior tibialis tendon (PTT) degeneration and spring and deltoid ligament insufficiency. Some repair techniques reconstruct the spring ligament. A current repair technique involves suture-tape augmentation with anchors from the calcaneus to the navicular. We have developed a novel tendon graft reconstruction repair utilizing graft tissue from the medial talar neck to the navicular. The purpose of this study was to compare these two reconstruction methods in a cadaveric flatfoot model. Methods: Five matched-pair fresh-frozen cadaver feet (four female and one male, age 76.4±11.3 years) underwent flatfoot creation and reconstruction. The feet were cyclically loaded with 16,000 cycles from 200 N to 1.5× body weight at 1 Hz. Each foot was randomly assigned to undergo either suture-tape augmentation or tendon graft reconstruction. Radiographic parameters, foot motion, and pressure mapping were measured before loading, after loading, and after repair. Ramp-to-failure testing was conducted as well. Results: The cadaveric flatfoot model was successfully created, demonstrated by significant changes in Meary’s angle (mean change = 7.4°, &lt; .05), talonavicular coverage (mean change = 14.7°, p &lt; .05), and medial cuneiform height (mean change = 5.6mm, p &lt; .05). The tendon graft technique (mean change = 7.1°, p &lt; .05) resulted in more significant improvements in Meary’s angle compared to the other technique (mean change = 2.3°). There were no significant differences in inversion and eversion data between repair techniques. The tendon graft technique had a significantly higher failure threshold (mean failure = 2864.9 N, p&lt; 0.05) compared to the other technique (mean failure = 2594.8N), and a lower failure rate (1/5 failed with tendon graft vs. 3/5 failed with suture tape). Conclusion: Both techniques successfully restored arch alignment and preserved hindfoot motion in a cadaveric flatfoot model. However, the tendon graft technique demonstrated greater improvement in alignment and failure resistance. Further evaluation of the tendon graft technique is necessary to determine its viability as a substitute for stabilizing procedures like osteotomies or fusions. Given the potential for host tissue incorporation, the tendon graft technique may offer better long-term durability. Foot Specimen Set Up for Loading Figure 1: (A) Lateral view of the foot with retro-reflective markers and of the Achilles tendon sandwiched between sailcloth. (B) Anterior view of the foot with retro-reflective markers.

Research Type: Level 5 - Case report, Expert opinion, Personal observation Introduction/Purpose: Achieving accurate syndesmotic reduction is essential for outcomes. Traditional parameters such as tibiofibular overlap/clear space have demonstrated inconsistent reliability. Sagittal tibiofibular overlap has increased in popularity but may be effected by rotation. While intraoperative CT scan/arthroscopy provide enhanced accuracy, their invasiveness and limited availability highlight the need for a practical, fluoroscopy-based intraoperative tool. Talar subluxation following syndesmotic fixation is a commonly seen phenomena and may suggest syndesmotic malalignment. Despite this, no studies have yet elucidated the specific modes of malreduction and their impact on sagittal plane talar displacement. The purpose of this cadaveric study was to investigate whether anterior/posterior talar subluxation can reliably indicate syndesmosis malreduction and to identify which simulated malreduction conditions are most closely associated with this radiographic finding. Methods: Twelve fresh frozen cadaveric trans-knee amputated specimens were subjected to six controlled fibular malreduction conditions: · Anterior displacement (5 mm) +/- overcompression · Posterior displacement (5 mm) +/-overcompression · External rotation (15°) +/- overcompression Each condition was tested with and without overcompression using a custom-designed displacement block. After the initial trials, each malreduction condition was repeated after complete transection of the deltoid ligament. For each malalignment condition, perfect lateral fluoroscopic images and weightbearing computed tomography (WBCT) scans were obtained. Tibiotalar Distance (TTD) was measured across both imaging modalities to assess anterior/posterior talar subluxation. Kruskal-Wallis tests were conducted to assess significant factors, and paired Wilcoxon rank-sum tests were used to evaluate potential outliers. Results: Fluoroscopic Tibiotalar Distance (TTD) measurements demonstrated variable responses to syndesmotic malalignment, with notable trends despite statistical variability. Fluoroscopic analysis identified significant cadaver variability (p &lt; 10⁻⁹, Kruskal-Wallis), but no definitive association was found between TTD and specific malalignment conditions (p = 0.57). However, a significant effect was observed for translation and rotation (p = 0.04), suggesting a possible correlation. However, external rotation (15°) demonstrated a significant increase in TTD (p = 0.05), highlighting a potential relationship with sagittal plane displacement. WBCT findings mirrored fluoroscopic trends, confirming that TTD variations were observed across malalignment conditions, although without reaching statistical significance (p &gt; 0.2). Importantly, WBCT emphasized the influence of patient-to-patient variability, suggesting that TTD’s utility may depend on individual anatomical differences. Conclusion: Talar subluxation following syndesmotic fixation is a commonly seen phenomena and may suggest syndesmotic malalignment. In our investigation fluoroscopic and WBCT findings demonstrated trends of increased TTD in these malalignment conditions demonstrating talar subluxation is evident with syndesmotic malreduction states. While these displacement patterns suggest some utility of TTD as an adjunctive marker in intraoperative syndesmotic assessment, the modest trends observed highlight the need for additional means of assessment. Future work should focus on developing more precise radiographic parameters and integrating complementary assessment techniques to enhance the accuracy of syndesmotic reduction evaluation.