Interosseous Ligament Research Articles

Portable dynamic ultrasonography is a useful tool for the evaluation of suspected syndesmotic instability: a cadaveric study

PurposePortable ultrasonography (P-US) is increasingly used to diagnose syndesmotic instability. The aim of this study was to evaluate syndesmotic instability by measuring the distal tibiofibular clear space (TFCS) in a cadaveric model using P-US with progressive stages of syndesmotic ligamentous transection under external rotation stress.MethodsTen fresh lower leg cadaveric specimens amputated above the proximal tibiofibular joint were used. Using P-US, the TFCS was evaluated in the intact stage and after progressive sectioning of the (1) anterior–inferior tibiofibular ligament (AITFL), (2) interosseous ligament (IOL), and (3) posterior–inferior tibiofibular ligament (PITFL). The TFCS was measured in both the unstressed (0 Nm) state and with 4.5, 6.0, 7.5, and 9.0 Nm of external rotation stress using a bone hook placed on the first metatarsal bone at each stage of ligamentous transection stage using both P-US and fluoroscopy.ResultsWhen assessed with P-US, partial syndesmotic injury encompassing the AITFL and IOL resulted in significant TFCS widening at 4.5 Nm of external rotation torque when compared to intact state with a TFCS-opening of 2.6 ± 2 mm, p = 0.01. In contrast, no significant differences in TFCS were detected using fluoroscopy. Only a moderate correlation was found between P-US and fluoroscopy.ConclusionP-US is a useful tool in diagnosing syndesmotic instability during external rotation stress examination. TFCS-opening increased as additional ligaments of the syndesmosis were transected, and application of 4.5 Nm torque was sufficient to detect a difference of 2.6 mm after the IOL cut.

Morphology of the Lisfranc Joint Complex

Lisfranc injuries are complicated injuries of the tarsometatarsal joint with high rates of sequelae. Both anatomy and injury of the Lisfranc joint are variably documented. Descriptions of these injuries and their associated structures vary greatly. The most injured structures are those of the Lisfranc joint complex, which involves the medial cuneiform, second and third metatarsals, and the dorsal, interosseous, and plantar Lisfranc ligaments. This study sought to examine morphology of the Lisfranc joint in cadavers. Twenty-two embalmed cadaveric feet were dissected (13 male, 9 female, 80.3 years ± 14.03) to isolate the bones and ligaments of the Lisfranc joint complex. The dorsal, interosseous, and plantar Lisfranc ligaments were present in each specimen. Each ligament was measured and morphology noted. The dissected dorsal Lisfranc ligament had consistent morphology (mean=10.8 mm ± 1.79). The interosseous Lisfranc ligament had a consistent path, but 11/17 of specimens possessed a connection to the plantar Lisfranc ligament. The plantar Lisfranc ligament demonstrated wide variability with a Y-variant (n=3) and a fan-shaped variant (n=14). Ligament thickness was greatest in the interosseous Lisfranc ligament (mean=13.74 ± 3.08) and least in the dorsal Lisfranc ligament (mean=1.36 ± 0.42). While the objective of defining joint and ligament morphology was achieved, further questions were raised. Variations of the interosseous and plantar Lisfranc ligament may play a role in susceptibility to joint injury, and arthritic changes to the joints examined raise questions regarding the prevalence of arthritis in the uninjured Lisfranc joint.

A fluid-structure interaction investigation of intra-articular pressure and ligament in wrist joint

Understanding the stresses on the scapholunate interosseous ligament (SLIL) and its interaction with synovial fluid pressure could be vital to improve wrist treatment for various wrist conditions such as arthritis, sprains and tendonitis. This study investigated the interaction between the intra-articular pressure, specifically the synovial fluid pressure change and the SLIL stresses in a computational model during wrist radioulnar deviation (RUD). Magnetic resonance imaging (MRI) scans were used to acquire the anatomical model of the carpal bones and ligament, while the kinematics of scaphoid and lunate were obtained through dynamic computerized tomography (CT) scans. A two-way fluid–structure interaction (FSI) was used to model the dynamics between the scaphoid and lunate, the SLIL, and the synovial fluid. The synovial fluid pressure change was found to be small (−4.86 to 3.23 Pa) and close to that simulated in a previous work without the SLIL (−1.68 to 2.64 Pa). Furthermore, peaks of maximum fluid pressure were found to trail the peaks of ligament stress. Therefore, it is suggested that the influence of synovial fluid pressure on the ligament in the SLIL model is negligible and simulations of the scapholunate joint could forego fluid-structure interactions. Future studies can instead explore other structures in the carpus that can possibly contribute to the ligament stresses. Clinically, treatments can be targeted at these areas to help prevent or slow the progression of ligament injuries into serious consequences like the degenerative joint disease.

Arthroscopic Dorsal Ligamentocapsulodesis in the Treatment of Isolated Lunotriquetral Interosseous Ligamentous Injury: A Retrospective Case Series of 22 Patients.

Background: The literature is scarce regarding isolated tears of lunotriquetral interosseous ligament (LTIL). The purpose of this study was to present mid-term clinical and functional results of arthroscopic dorsal ligamentocapsulodesis in the treatment of isolated LTIL tears. Methods: Twenty-two patients (8 females, 14 males; mean age: 31 years; age range: 18-42) with isolated LTIL tears verified by wrist arthroscopy were retrospectively reviewed and included in the study. The mean follow-up was 55 months (range: 24-84). The modified Mayo wrist score, visual analog scale (VAS), flexion and extension deficits of passive wrist range of motion (ROM), pain-free ROM with forced wrist extension and grip strength were measured in all patients preoperatively and at final follow-up. Results: The mean modified Mayo wrist score significantly improved from 50 ± 10.29 preoperatively (range: 30-65) to 86 ± 11.61 (range: 60-100) at the final follow-up (p < 0.001). The mean VAS score significantly improved from 7.1 ± 0.83 (range: 6-8) preoperatively to 2.2 ± 1.35 (range: 0-6; p < 0.001) at the final follow-up. At the final follow-up examination, the forced wrist extension was painless in all but three patients who developed pain at 70º, 75º and 80º of extension, respectively. The mean strength of hand grip significantly increased from 38.6 ± 9.68 (range: 24-54) kg to 49.5 ± 12.36 (range: 33-66) kg at the final assessment (p < 0.001). No major complications were observed during or after the procedure. Conclusions: With the encouraging mid-term outcomes and a lower complication rate, arthroscopic LTIL dorsal ligamentocapsulodesis seems to be a safe and effective surgical technique in improving functional outcomes and reducing pain in patients with isolated LTIL tears. Level of Evidence: Level IV (Therapeutic).

Suture button fixation method used in the treatment of syndesmosis injury: A biomechanical analysis of the effect of the placement of the button on the distal tibiofibular joint in the mid-stance phase with finite elements method

PurposeThe purpose of this study is to research the effect of suture button (SB) fixation, a method used at the treatment of ankle syndesmosis injury, which was applied in various angles, pretension force, and levels, on the distal tibiofibular joint (DTFJ) in the mid-stance phase, with the help of three-dimensional finite elements method (FEM) MethodThe ankle of a healthy individual was digitally analyzed by a finite element method-based package computer program. Then, anterior inferior tibiofibular ligament (AITFL), interosseous ligament, posterior inferior tibiofibular ligament (PITFL) and deltoid ligament (DL) were cut and force and rotation has been applied to the proximal tibia, resulting in syndesmosis injury. Then, various suture button applications on the injured model have been analyzed. Three parameters have been changed; which were divergence in the axial plane (20°, 30°, 40°), distance from the ankle (2, 3, 4 cm), and pretension force (200, 300, 600 N) ResultsAs the result of this study, the rotation, change in the gap between the distal tibia and distal fibula, and the displacements of the fibula in the x and y axes have been obtained, and numerical results were evaluated. As the force increased, rotation, change in the gap between the distal tibia and distal fibula, and the displacements of the fibula decreased. As suture button application rotation increased, change in the gap between the distal tibia and distal fibula, and displacements of the fibula increased. As the distance from the ankle increases and reaches a certain level, the results converge to those of the healthy model; in the proximal, it diverges from healthy results. ConclusionIn the study, it has been shown that abnormal tibiofibular joint movements can be prevented with suture button application, and optimum application parameters (divergence in the axial plane, distance from the ankle, and pretension force) are given for proper reduction.

Analysis and validation of a 3D finite element model for human forearm fracture.

Most researchers have performed finite element (FE) analysis of the human forearm fracture by exploring the strength and load transmission of the bones. However, few studies concentrated a complete simulation of the whole forearm complex including ligaments. This paper aims to investigate the load transmission through the bones, contact stress at the joints and strain in the ligaments by using an elaborate FE model, further validating the fracture condition for human forearm. The interosseous ligament was separated into three regions based on the distance to the proximal and distal ends. The FE simulation results were slightly more or less than a previous experimental data in the literature, but generally provided a close approximation of the bone and ligament behaviors. Compared with the experiment results under different loading conditions, maximum contact stress at the proximal radio ulnar joint (PRUJ) and distal radio ulnar joint (DRUJ) of the simulations was higher with an average of 13.4%, and peak strain in the interosseous ligament (IOL) was lower with an average of 11.0%. Under 10kg load, the maximum stress in the radius (2.25 MPa) was less than double the value in the ulna (1.43 MPa). Finally, the FE model has been validated with the onset and location of the Colles' fracture in the literature. This study will provide a great benefit in terms of surgical and medical applications related to forearm fracture that require an extensive knowledge of the behavior of the bones and ligaments under various loading conditions.

Isolated injuries to the lateral ankle ligaments have no direct effect on syndesmotic stability.

This study aim was to detect the impact of lateral ankle ligaments injury on syndesmotic laxity when evaluated arthroscopically in a cadaveric model. The null hypothesis was that lateral ankle ligament injury does not affect the stability of syndesmosis. Sixteen fresh-frozen above-knee amputated cadaveric specimens were divided into two groups of eight specimens that underwent arthroscopic evaluation of the distal tibiofibular joint. In both the groups, the assessment was first done with all syndesmotic and ankle ligaments intact. Thereafter, Group 1 underwent sequential transection of the three lateral ankle ligaments first to identify the effects of lateral ligament injury: (1) anterior talofibular ligament (ATFL), (2) calcaneofibular ligament (CFL), (3) posterior talofibular ligament (PTFL), then followed by the syndesmotic ligaments, (4) AITFL, (5) Interosseous ligament (IOL), and (6) PITFL. Group 2 underwent sequential transection of the (1) AITFL, (2) ATFL, (3) CFL, (4) IOL, (5) PTFL, and (6) PITFL, which represent the most commonly injured pattern in ankle sprain. In all scenarios, four loading conditions were considered under 100N of direct force: (1) unstressed, (2) a lateral fibular hook test, (3) anterior to posterior (AP) fibular translation test, and (4) posterior to anterior (PA) fibular translation test. Distal tibiofibular coronal plane diastasis at the anterior and posterior third of syndesmosis, as well as AP and PA sagittal plane translation, were arthroscopically measured. The distal tibiofibular joint remained stable after transection of all lateral ankle ligaments (ATFL, CFL, and PTFL) as well as the AITFL. However, after additional transection of the IOL, the syndesmosis became unstable in both the coronal and sagittal plane. Syndesmosis laxity in the coronal plane was also observed after transection of the ATFL, CFL, AITFL, and IOL. Subsequent transection of the PITFL precipitated syndesmosis laxity in the sagittal plane, as well. The findings from the present study suggest that lateral ankle ligament injuries itself do not directly affect the stability of syndesmosis. However, if it combines with IOL injuries, even partial injuries cause syndesmotic laxity. As a clinical relevance, accurate diagnosis is the key for surgeons to determine syndesmosis fixation whether there is only AITFL injury or combined IOL injury in concomitant acute syndesmotic and lateral ligament injury.

An algorithmic diagnostic approach to scapholunate ligament injuries based on comparison of X-ray examinations and arthroscopy in 414 patients

Conventional X-ray imaging is usually the first diagnostic assessment after clinical examination in case of suspected scapholunate interosseous ligament (SLIL) injury. Nevertheless, there is no consensus on the norms of the scapholunate distance (SLD) or carpal angles. Therefore, we aimed to determine the utility of static and dynamic radiographs in the diagnostic of an SLIL injury in comparison with the reference standard arthroscopy. We retrospectively analyzed the preoperative X-ray series and surgical records of arthroscopies of 414 patients. Radiological assessment included conventional static X-rays in the posteroanterior (PA) projection, clenched fist views in ulnar and radial deviations, in which the SLD at the midportion of the scapholunate (SL) joint was measured. The scapholunate angle (SLA) and radiolunate angle (RLA) were measured on lateral wrist radiographs. Receiver operating characteristic (ROC) curves were created to determine possible cut-off points of the radiological indices for the diagnosis of SLIL injury. Further, a logistic regression with the parameters having the highest area under the curve (AUC) was calculated. We found that SLD in ulnar inclination (AUC= 0.774), SLD in PA projection (AUC=0.748), and SLA (AUC=0.737) had the highest diagnostic value. The AUC of the combination of these three parameters was 0.822 for all patients with any SLIL lesion and 0.850 for patients with SLIL lesions of 3-4 Geissler grade. Further investigation of SLIL pathology would be appropriate in the case of SLD in ulnar inclination of 2.7mm, SLD in PA projection of 1.9mm and SLA of 63°.

Kinematic 4D CT case-control study of wrist in dart throwing motion "in vivo": comparison with other maneuvers.

To compare the diagnostic performance of scapholunate gap (SLG) measurements acquired with dart throwing (DT), radio-ulnar deviation (RUD), and clenching fist (CF) maneuvers on 4D CT for the identification of scapholunate instability. In this prospective study, 47 patients with suspected scapholunate interosseous ligament (SLIL) tears were evaluated from March 2015 to March 2020 with semiautomatic quantitative analysis on 4D CT. Five parameters (median, maximal value, range, and coefficient of variation) for SLG, lunocapitate angle (LCA), and radioscaphoid angle (RSA) obtained during DT maneuver were evaluated in patients with and without SLIL tears. CT arthrography was used as the gold standard for the SLIL status. The SLG values obtained were also compared with those obtained during CF and RUD maneuvers. Significant differences in all SLG- and LCA-derived parameters are found between patients with and without SLIL tears with DT (p < 0.003). The best diagnostic performance for the diagnosis of SLIL tears was obtained with median and maximal SLG values (sensitivity and specificity of 86-89% and 95%) and with maximal and range LCA values (sensitivity and specificity of 86% and 74%). No significant differences were observed for RSA values (p > 0.275). The SLG range obtained with DT maneuver was the only dynamic parameter statistically different between patients with partial and complete torn SLIL (p = 0.037). 4D CT of the wrist during DT showed a similar performance than RUD and a better performance than CF for the differentiation between patients with and without SLIL tears. • Four-dimensional computed tomography can dynamically assess scapholunate instability. • The best results for differentiating between patients with and without SLIL tears were obtained with SLG median and maximal values. • The dart throwing and radio-ulnar deviation maneuvers yielded the best results for the dynamic evaluation of scapholunate instability.

The prevalence of posterior inferior tibiofibular ligament and inferior tibiofibular transverse ligament injuries in syndesmosis-injured ankles evaluated by oblique axial magnetic resonance imaging: a retrospective study

BackgroundTransverse ligament and posterior inferior tibiofibular ligament injuries have not been investigated till date because these are difficult to evaluate using standard magnetic resonance imaging. This study aimed to investigate the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles using oblique axial magnetic resonance imaging.MethodsThe patients who were diagnosed with syndesmosis injury using magnetic resonance imaging (MRI) within 7 days of the trauma were included. Patients with concomitant fractures were excluded. A total of 34 patients (1 woman and 33 men) with an average age of 22 years (range, 14–64 years) were included. The anterior inferior tibiofibular, interosseous, transverse, and posterior inferior tibiofibular ligaments were classified as intact, partial tear, or complete tear using usual axial and oblique axial MRIs.ResultsThere were 8 (23.5%) ankles with an intact, 21 (61.8%) ankles with a partially torn, and 5 (14.7%) ankles with a complete tear of transverse ligament. There were 20 (58.8%) ankles with an intact, 12 (35.3%) ankles with a partially torn, and 2 (5.9%) ankles with a complete tear of posterior inferior tibiofibular ligament. Overall, 50% of the transverse ligament injuries occurred without posterior inferior tibiofibular ligament involvement.ConclusionsThe oblique axial magnetic resonance imaging scan revealed that the prevalence of transverse ligament and posterior inferior tibiofibular ligament injuries in syndesmosis-injured ankles were 76.5 and 41.2%, respectively.

Comparative Analysis of Subtalar Ligaments Between Patients With Talocalcaneal Coalition and Control Subjects Using 3-Dimensional Magnetic Resonance Imaging.

The purpose of this study was to find the differences in the subtalar ligaments between patients with talocalcaneal (TC) coalition and control subjects using 3-dimensional isotropic magnetic resonance imaging. Magnetic resonance imaging of 27 ankles with TC coalition and 27 age- and sex-matched controls were retrospectively reviewed. Absence of cervical ligament, anterior capsular ligament (ACL), interosseous TC ligament (ITCL), and partial or complete absence of 3 roots of the inferior extensor retinaculum was analyzed. Thickness and width of ACL and ITCL were measured when possible. Absence of ACL and ITCL was significantly more frequent in TC coalition patients than in controls (59.2% vs 7.4%, P < 0.0001; 44.4% vs 7.4%, P = 0.004). Absence of cervical ligament and 3 roots of the inferior extensor retinaculum did not differ between the 2 groups. Thickness and width of ACL were significantly smaller in TC coalition patients than in control subjects (0.81 ± 0.23 vs 1.27 ± 0.41 mm, P < 0.0001; 5.26 ± 1.17 vs 7.07 ± 1.46 mm, P = 0.001). Thickness and width of ITCL did not differ between the 2 groups. In the TC coalition group, the absence of ACL and ITCL did not differ according to coalition type, patient demographics, and magnetic resonance imaging units. Anterior capsular ligament and ITCL are frequently absent in TC coalition patients. Even when present, the ACL is attenuated in TC coalition patients compared with controls.

Essex-Lopresti Lesions and Longitudinal Radioulnar Instability: A Narrative Review.

An Essex-Lopresti injury (ELI) is classically described as a radial head fracture with a concomitant interosseous ligament complex (IOC) injury. However, multiple injury patterns may be present, and an interosseous membrane (IOM) injury should be evaluated for in any axial load injury through the forearm. ELI may result in longitudinal radioulnar instability (LRUI). Diagnosis of an IOC injury can be difficult. Evaluation begins with standard wrist and elbow radiographs and is supplemented with radiographs and intraoperative maneuvers to assess for proximal radial migration. Magnetic resonance imaging and ultrasonography may be useful in the acute setting, although indications and the clinical importance of the findings remain unclear. Surgical management of an acute ELI is focused on restoration of radial length and temporary distal radioulnar joint (DRUJ) stabilization. Radial head excision in the acute setting should be approached with caution because proximal migration may not be present acutely but may develop over time. The indication for acute IOM repair and reconstruction remains unclear. Surgical management of a chronic ELI is focused on restoration of radial length, wrist leveling, and treatment of degenerative changes (either at the radiocapitellar joint or the DRUJ). Reconstruction of the central band can restore forearm load transfer and produce favorable functional outcomes, but its indications continue to be debated.

Minimum 5-Year Outcomes of Dorsal Intercarpal Ligament Capsulodesis With Scapholunate Interosseous Ligament Repair for Subacute and Chronic Static Scapholunate Instability: A Clinical Series of 5 Patients

PurposeTreatment of subacute and chronic static scapholunate instability remains challenging. We aimed to determine 5- to 10-year outcomes of dorsal intercarpal ligament capsulodesis with scapholunate interosseous ligament repair for subacute and chronic static scapholunate instability.MethodsSix patients with subacute and chronic static scapholunate instability underwent dorsal intercarpal ligament capsulodesis with scapholunate interosseous ligament repair between 2011 and 2015, and 5 of them were followed for at least 5 years after surgery. The clinical and radiological results were retrospectively investigated. All patients were male, and the mean age at surgery was 37 years (range, 21–47 years). The mean period from injury to surgery was 26.2 months (range, 2–113 months). The surgical procedure was a modification of a method reported by Szabo et al.ResultsThe mean postoperative follow-up period was 8.1 years (range, 5.1–9.5 years). Median Disabilities of the Arm, Shoulder, and Hand and Mayo wrist scores improved from 23.3 to 1.7 and from 55 to 80, respectively, from before surgery to the final follow-up. Although the median flexion angle tended to be smaller, the median extension angle tended to be greater than before surgery. The median percent grip strength increased from 72.3% before surgery to 99.2% at the final follow-up. The median scapholunate gap improved from 4.2 mm before surgery to 2.1 mm at the final follow-up. The median scapholunate angle also improved from 95.7° before surgery to 71.3° at the final follow-up. Osteoarthritic changes were observed in 2 of 5 patients at the final follow-up.ConclusionsThe scapholunate gap in all patients was within the normal range after a mean of 8.1 years of follow-up. Dorsal intercarpal ligament capsulodesis with scapholunate interosseous ligament repair is considered a good alternative for subacute and chronic static scapholunate instability based on these 5- to 10-year outcomes.Type of study/level of evidenceTherapeutic IV.

Comparison of Several Combinations of Suture Tape Reinforcement and Suture Button Constructs for Fixation of Unstable Syndesmosis.

The purpose of this study was to arthroscopically evaluate syndesmotic stability after fixation with several combinations of suture buttons (SBs) and suture tape reinforcement in a completely unstable cadaver model. Fifteen cadaver above-knee specimens underwent sequential ligament transection and fixation to create six experimental models: (1) intact model, (2) after complete disruption of the syndesmotic ligaments, and after repair with either suture tape reinforcement (3), suture tape reinforcement with a single SB (4), suture tape reinforcement with two diverging SBs (5), or two diverging SBs alone (6). Instability measurements included anterior and posterior tibiofibular spaces measured arthroscopically under 100 N coronal stress, tibiofibular anteroposterior and posteroanterior translation in sagittal plane measured arthroscopically under sagittal stress of 100 N, and anterior tibiofibular space measured directly with a caliper under external rotation torque of 7.5 N·m. Instability measurements taken after each fixation method were compared with the uninjured model and with the complete unstable model using the Wilcoxon signed-rank test. Fixation using a combination of one SB and singular suture tape reinforcement augmentation provided stability similar to the intact stage (coronal anterior space 1.24 versus 1.15, P = 0.887; coronal posterior space 1.63 versus 1.64, P = 0.8421; anteroposterior translation 0.91 versus 0.46, P = 0.003; posteroanterior translation 0.51 versus 0.57, P = 0.051; external rotation anterior tibiofibular space 1.08 versus 0.55, P = 0.069). Moreover, adding a second SB led to further gains in fixation stability. This study suggests that although a destabilizing syndesmotic injury that includes the anterior inferior tibiofibular ligament, interosseous ligament, and posterior inferior tibiofibular ligament is not adequately stabilized by either one or two SBs, the addition of a suture tape reinforcement to even one SB restores syndesmotic stability to the preinjury level.

Outcomes after Bone-Ligament-Bone Intercarpal Ligament Reconstruction.

Numerous surgical reconstructive techniques have been described for chronic scapholunate and lunotriquetral interosseous ligament instability. The authors retrospectively reviewed 16 consecutive patients who underwent bone-ligament-bone reconstruction for scapholunate or lunotriquetral intraosseous ligament predynamic and dynamic instability at a single tertiary care institution from 2013 to 2019. Clinical and radiographic outcomes, and complications, were recorded. Eleven patients had bone-ligament-bone reconstruction for scapholunate ligament injuries and five for lunotriquetral instability. Fourteen patients (87.5 percent) underwent diagnostic arthroscopy before bone-ligament-bone reconstruction, with nine of 14 having grade 3 and four of 14 having grade 4 injury. Capitohamate bone-ligament-bone grafts were used in nine patients (56 percent) and the graft was taken from Lister tubercle in seven (44 percent). The average age at surgery was 37 years. The average follow-up was 60.6 weeks. There were no significant differences between preoperative and postoperative radiographic parameters. Median postoperative wrist flexion was 45 degrees, and mean postoperative wrist extension was 53 degrees, which were significantly less than contralateral flexion (85 degrees; p < 0.0001) and extension (78 degrees; p < 0.0001). Thirty-eight percent of patients complained of persistent pain at final follow-up, and two patients (13 percent) underwent salvage procedures, both at approximately 6.5 months after the index reconstruction. Short-term outcomes of bone-ligament-bone reconstruction for early-stage scapholunate and lunotriquetral ligament injuries reveal many patients with residual postoperative wrist pain and disability, and almost uniform limitations in flexion-extension motion. Therapeutic, IV.

A Large Animal Model for Orthopedic Foot and Ankle Research.

Trauma to the soft tissues of the ankle joint distal syndesmosis often leads to syndesmotic instability, resulting in undesired movement of the talus, abnormal pressure distributions, and ultimately arthritis if deterioration progresses without treatment. Historically, syndesmotic injuries have been repaired by placing a screw across the distal syndesmosis to provide rigid fixation to facilitate ligament repair. While rigid syndesmotic screw fixation immobilizes the ligamentous injury between the tibia and fibula to promote healing, the same screws inhibit normal physiologic movement and dorsiflexion. It has been shown that intact screw removal can be beneficial for long-term patient success; however, the exact timing remains an unanswered question that necessitates further investigation, perhaps using animal models. Because of the sparsity of relevant preclinical models, the purpose of this study was to develop a new, more translatable, large animal model that can be used for the investigation of clinical foot and ankle implants. Eight (8) skeletally mature sheep underwent stabilization of the left and right distal carpal bones following transection of the dorsal and interosseous ligaments while the remaining two animals served as un-instrumented controls. Four of the surgically stabilized animals were sacrificed 6 weeks after surgery while the remaining four animals were sacrificed 10 weeks after surgery. Ligamentous healing was evaluated using radiography, histology, histomorphometry, and histopathology. Overall, animals demonstrated a high tolerance to the surgical procedure with minimal complications. Animals sacrificed at 10 weeks post-surgery had a slight trend toward mildly decreased inflammation, decreased necrotic debris, and a slight increase in the healing of the transected ligaments. The overall degree of soft tissue fibrosis/fibrous expansion, including along the dorsal periosteal surfaces/joint capsule of the carpal bones was very similar between both timepoints and often exhibited signs of healing. The findings of this study indicate that the carpometacarpal joint may serve as a viable location for the investigation of human foot and ankle orthopedic devices. Future work may include the investigation of orthopedic foot and ankle medical devices, biologic treatments, and repair techniques in a large animal model capable of providing translational results for human treatment.

Maisonneuve Fractures of the Ankle: A Critical Analysis Review.

Maisonneuve fractures (MFs), originally described as subcapital (high) fibular fractures with additional injury to the anterior and interosseous tibiofibular ligaments, display a variable injury pattern, ranging from stable to highly unstable fractures. The high incidence of associated fractures of the posterior malleolus, the medial malleolus, and the anterolateral distal tibia (the "anterior malleolus") as well as the variable position of the fibula in the fibular notch (FN) warrant preoperative examination via computed tomography (CT). The main goal of treatment is anatomic reduction of the distal fibula into the FN, which requires prior reduction of displaced posterior malleolar fractures, if present, to restore the integrity of the FN. Open reduction of the distal fibula into the FN and fixation with 2 transsyndesmotic screws or fixation with a screw(s) and suture-button implant, under direct vision, on the lateral aspect of the ankle joint and anterior tibiofibular alignment are preferred over closed reduction to avoid sagittal or rotational malpositioning, which is associated with an inferior outcome. Intra- or postoperative 3D CT visualization is essential for assessment of the accuracy of the reduction of the distal fibula into the FN.

Dorsal scapholunate interosseous ligament: ultrasound evaluation between dominant and non-dominant wrist in young sports patients.

The dorsal component of the scapholunate ligament, is the strongest component, in fact it has a maximum tensile strength of 300N and mainly controls flexion and extension. In a recent study, the thickness and length of the dorsal component of SLIL was measured using ultrasound image, the length of the dorsal scapholunate ligament was 7.5mm ± 1.4mm and the thickness of 1.8mm ± 0.4mm. We evaluate 60 wrists of 30 young athletic volunteers with ultra-sound image, comparing the thickness variations of the dorsal component of SLIL between the dominant and non-dominant wrist, to confirm our hypothesis that the dorsal component SLIL has proprioceptive activity and therefore the thickness of the ligament increases in following wrist activity. With a high-frequency ultrasound probe > 15MHz (Sonoscape X3 Pro) we evaluated 60 wrists of 30 young men (16 males and 14 females, 20-38years old) manual sports volunteers (10 tennis players, 8 padel players, 7 swimmers, 5 weight lifters) with no recent ligament injuries of the hand or wrist to participate in the study, we compared the dorsal component of SLIL between the dominant and non-dominant wrist. Dorsal SLIL was visualized in all 60 volunteers wrists. We measured an average scapholunate dorsal ligament length 7.7mm and average thickness of 2.3mm in the dominant wrist and average 7.2mm in length and average 1.9mm thickness in the non dominant wrist. The mean dorsal scapholunate interval was average 4.9mm and the mean central interval was average 2.1mm in the dominant wrist and 4.7mm and 1.8mm in the non dominant wrist, so that meas-urements remained unchanged with those reported by previous authors. In our study we ultrasonographically measured an average scapholunate dorsal ligament length 7.7mm and average thickness of 2.3mm in the dominant wrist and average 7.2mm in length and average 1.9mm thickness in the non dominant wrist. This confirms our hypothesis that there is a direct stimulus on the ligamentous component of the dor-sal SLIL in the dominant wrist following repeated uses and activities such as to cause an increase in thickness of the dorsal ligament to highlight the possibility of a proprioceptivity of the ligament if subjected to continuous training. IV.

Biomechanical Finite Element Method Model of the Proximal Carpal Row and Experimental Validation.

The Finite Element Method (FEM) models are valuable tools to create an idea of the behavior of any structure. The complexity of the joints, materials, attachment areas, and boundary conditions is an open issue in biomechanics that needs to be addressed. Scapholunate instability is the leading cause of wrist pain and disability among patients of all ages. It is needed a better understanding of pathomechanics to develop new effective treatments. Previous models have emulated joints like the ankle or the knee but there are few about the wrist joint. The elaboration of realistic computational models of the carpus can give critical information to biomedical research and surgery to develop new surgical reconstructions. Hence, a 3D model of the proximal carpal row has been created through DICOM images, making a reduced wrist model. The materials, contacts, and ligaments definition were made via open-source software to extract results and carry on a reference comparison. Thus, considering the limitations that a reduced model could carry on (unbalanced forces and torques), the stresses that result in the scapholunate interosseous ligament (SLIL) lead us to a bones relative displacement, which support the kinematics hypothesis in the literature as the distal carpal row moves as a rigid solid with the capitate bone. Also, experimental testing is performed, successfully validating the linear strength values of the scapholunate ligament from the literature.

A Novel Operative Approach to the Treatment of Posterior Malleolus Fractures

Background: Posterior malleolar fractures are a common subtype of ankle fractures. The management of these fractures remains controversial, though there has been a move toward more operative management in recent years. The operative approach most commonly used to treat these fractures is posterolateral. This method has several drawbacks including the amount of retraction required on already traumatized skin, the risk of damaging the posterior interosseous tibio-fibular ligament, and the difficulty visualizing both the distal fibular and posterior malleolar fractures. We describe a novel operative approach for visualizing and treating these fractures and report on our results. Method: This was a retrospective review of prospectively collected data. Data from 2 orthopedic trauma units where this technique is used was analyzed. Demographic and radiographic data was recorded, and a chart review was conducted to identify any noted complications. Results: On analysis of medical records, 50 patients were identified who had been operated on using this technique. When classified using the Bartonicek classification, 46% were type II, 36% were type III and 18% were type IV. Analysis of final x-rays showed that there was no incidence of implant failure or loss of reduction in this cohort. There were 2 complications recorded: 1 early wound dehiscence and 1 late infection giving an overall complication rate of 4%. Discussion: The technique described in this paper is a novel approach, which we feel offers several benefits. We demonstrated that this technique is safe with an incidence of early complications lower than figures commonly quoted for standard care of this cohort of patients. Level of Evidence: Level IV—case series