A Novel Simulation Model and Training Program for Minimally Invasive Surgery of Hallux Valgus.

BACKGROUND: Minimally invasive surgery (MIS) for hallux valgus (HV) has gained popularity. However, adopting this technique faces the challenges of a pronounced learning curve. This study aimed to address these challenges by developing and validating an innovative simulation model and training program, targeting enhanced proficiency in HV MIS. METHODS: A training program and a high-fidelity simulation model for HV MIS were designed based on experts' recommendations. Four foot and ankle surgeons without experience in MIS formed the novice group and took the program that encompassed six-session instructional lessons, hands-on practice on simulated models, and immediate feedback. The program concluded with a cadaveric surgery. Four foot and ankle experienced MIS surgeons formed the expert group and underwent the same procedure with one simulated model. Participants underwent blind assessment, including Objective Structured Assessment of Technical Skills (OSATS), surgical time, and radiograph usage. RESULTS: Expert evaluation of the simulation model indicated high satisfaction with anatomical representation, handling properties, and utility as a training tool. The expert group consistently outperformed novices at the initial assessment across all outcomes, demonstrating OSATS scores of 24 points (range, 23 to 25) versus 15.5 (range, 12 to 17), median surgical time of 22.75 minutes (range, 12 to 27) versus 48.75 minutes (range, 38 to 60), and median radiograph usage of 70 (range, 53 to 102) versus 232.5 (range, 112 to 280). DISCUSSION: Novices exhibited a significant improvement in OSATS scores from the fifth session onward (P = 0.01), reaching the desired performance of 20 points. Performance at the final training with the simulated model did not differ from cadaveric surgery outcomes for all parameters. CONCLUSION: This study validated a simulation model and training program, allowing nonexperienced HV MIS foot and ankle surgeons to enhance their surgical proficiency and effectively complete a substantial portion of the learning curve at the fifth session, and this performance was successfully transferred to a cadaver model. LEVEL OF EVIDENCE: III.

Safety and exposure area in three different posteromedial surgical approaches for the treatment of ankle fractures. A cadaveric study.

INTRODUCTION: This study aimed to compare the degree of posterior malleolar exposure, the tension of the flap containing the posteromedial neurovascular bundle (NVB), and the distance between the surgical incision and the NVB using three different posteromedial ankle approaches. METHODS: Three approaches were compared: medial posteromedial (MePM) modified posteromedial (MoPM) and posteromedial (PM). We measured the minimal tension of the flap containing the NVB that allowed proper exposure. In the second stage, an axial cut was performed, and we measured the degree of posterior malleolar exposure and the distance between the incision and the NVB RESULTS: There were significant differences between the three approaches examined regarding the degree of posterior malleolar exposure and distance from the incision to the NBV,favoring the PM approach (71,00% ± 1.83 and 25.50 mm ± 4.20). The PM approach provided a significantly lower tension to the flap containing the posteromedial NVB (6.18 N ± 1.28) compared to the other two approaches CONCLUSION: The PM approach achieved the highest degree of posterior malleolar exposure, the lowest tension to the posteromedial NVB, and the greatest distance between the incision and the NBV. Thus, we believe it should be considered the approach of choicefor large fractures of the posteromedial aspect of the PM.

Role of Lateral Ankle Ligaments in Vertical Stability of the Fibula: A Cadaveric Model.

BACKGROUND: In unstable ankle fractures, the role of the deltoid and syndesmosis ligaments has been widely studied. However, it is uncertain what the importance of the lateral ankle ligament complex (LALC) is in the vertical stability of the fibula. Given its anatomical position, it should prevent the proximal translation of the fibula. This study aims to evaluate the role of the LALC in stabilizing the fibula in the vertical plane. METHODS: Eleven below-knee cadaveric specimens were used in this study. Proximal traction of the fibula was performed by applying 50 N in the intact state and after sequential transection of the syndesmotic ligaments, anterior talofibular ligament (ATFL), and the calcaneofibular ligament (CFL). At each stage, the proximal displacement of the fibula was measured. One-way repeated measures analysis of variance with post hoc Bonferroni correction was carried out to determine any significant differences between the groups. A P value <.05 was considered statistically significant. RESULTS: The vertical displacement of the fibula in the intact state, and after sequential transection of syndesmotic ligaments, ATFL, and CFL was 1.96 ± 1.19 mm, 3.96 ± 1.33 mm, 5.9 ± 1.73 mm, and 10.22 ± 2.76 mm, respectively. There was no significant difference in the proximal displacement of the fibula between the intact and the syndesmotic ligaments groups (P < .05). However, when the syndesmotic ligaments were transected in conjunction with ATFL ± CFL, a significant difference was observed compared to the intact state (P < .001). CONCLUSION: The complete disruption of syndesmotic ligaments did not significantly increase the proximal displacement of the fibula. However, when the ATFL ± CFL were additionally disrupted, there was a significant increase in the vertical translation of the fibula. CLINICAL RELEVANCE: To our knowledge, this is the first study describing that LALC plays a paramount role in the vertical stability of the fibula. Concomitant syndesmosis and LALC should be suspected in an axially unstable fibular fracture with a significant proximal displacement.

Posterior Malleolar Fracture Assessment: An Independent Interobserver and Intraobserver Validation of Three Computed Tomography-Based Classifications.

BACKGROUND: Posterior malleolus fractures occur in up to 50% of all ankle fractures. Several classification systems exist for their characterization, especially under CT. However, those classifications do not report the level of agreement or do it incompletely. This study aims to independently assess three posterior malleolus fracture classifications (Haraguchi, Bartonícek/Rammelt, and Mason). METHODS: This study was designed according to the Guidelines for Reporting Reliability and Agreement Studies. Ninety-four CT scans of patients with ankle fractures that had posterior malleolus fractures were included. Posterior malleolus fractures were assessed by six evaluators (three attending foot and ankle surgeons and three orthopaedic surgery residents) according to Haraguchi, Bartonícek/Rammelt, and Mason classifications. All images were reassessed by the same evaluators in a random sequence 3 weeks later. The kappa (k) coefficient was used to determine the interobserver and intraobserver agreement. Statistical significance was established using P < 0.05 with a 95% confidence interval (CI). RESULTS: The interobserver agreement was moderate for Haraguchi, Bartonícek/Rammelt, and Mason classifications with a global k value of 0.52 (95% CI, 0.43 to 0.60), 0.53 (95% CI, 0.46 to 0.61), and 0.54 (95% CI, 0.47 to 0.62), respectively. The intraobserver agreement was substantial for Haraguchi, Bartonícek/Rammelt, and Mason classifications, with an overall k value of 0.70 (95% CI, 0.64 to 0.74), 0.73 (95% CI, 0.68 to 0.78), and 0.73 (95% CI, 0.69 to 0.78), respectively. Interobserver and intraobserver agreement among orthopaedic surgeons and residents had no significant difference. CONCLUSION: The current classifications for posterior malleolus fractures showed a substantial intraobserver agreement. Nevertheless, the interobserver agreement obtained was just moderate for all classifications, independent of the level of expertise of the evaluators.

The use of intraoperative comparative fluoroscopy allows for assessing sagittal reduction and predicting syndesmosis reduction in ankle fractures.

Intraoperative fluoroscopic parameters have shown to be poor predictors for ankle syndesmosis reduction, with up to 52% of syndesmotic malreduction (SMR) reported in the literature. Anteroposterior Tibio-Fibular index (APTF) was previously described to evaluate sagittal tibiofibular alignment in lateral ankle radiographs with a high correlation between both ankles in uninjured subjects. Reproducible intraoperative measurements for sagittal syndesmotic reduction are lacking. We propose the use of the "cAPTF," calculated as the absolute difference between the APTF of the non-injured and the operated ankle, to evaluate sagittal syndesmotic reduction. OBJECTIVE: Determine the predictive capability of cAPTF for SMR. METHOD: Prospective observational study. INCLUSION CRITERIA: patients with unstable ankle fractures requiring syndesmotic fixation, with a healthy contralateral ankle. Intraoperatively APTF was measured in both ankles after syndesmotic fixation. Postoperatively cAPTF was calculated. Only direct syndesmosis visualization through the lateral approach and AP and mortise views were used by surgeons to assess syndesmotic reduction. Quality of syndesmotic reduction was evaluated with bilateral postoperative CT. To estimate cAPTF discriminatory power for SMR, a receiver operative characteristic (ROC) curve was obtained and the area under the ROC curve was calculated. Youden index was used to determine the ideal cAPTF cut-off value for predicting SMR. For this determined cut-off value, sensitivity, specificity, and likelihood ratio were calculated. RESULTS: Fifty-two patients were included. Sixteen (30%) had SMR. Patients with SMR had a statistically significant higher cAPTF value than the well reduced (median 0.26 vs 0.09; P < 0.01). The cAPTF cut-off value to predict SMR was 0.161. A cAPTF greater than 0.161 had 100% sensitivity and 97,2% specificity for SMR. The area under the ROC curve was 0.99. CONCLUSION: Intraoperative cAPTF has excellent discriminatory power for predicting syndesmotic malreduction. We propose the routine use of intraoperative bilateral comparative fluoroscopy to assess sagittal syndesmotic reduction.

[An update on the work-up and management of ankle fractures: A literature review]. / Qué hay de nuevo en el estudio y manejo de las fracturas de tobillo: revisión de literatura.

Our understanding of the management of ankle fractures has significantly improved in recent years. Computerized axial tomography and better biomechanical insights have renewed the underlying concepts for both diagnosis and treatment. Notwithstanding, some aspects of the management of malleolar fractures still lack consensus. This review aims to update concepts on the study and management of ankle fractures. Stability, radiological studies, computerized axial tomography, management of associated ligament injuries (deltoid ligament and syndesmosis), and posterior malleolus fractures are covered in the article. The authors opinions and the evidence are discussed for each question.

El conocimiento acerca del manejo de las fracturas de tobillo ha tenido un gran crecimiento los últimos años. La tomografía axial computarizada y el mejor entendimiento biomecánico han renovado conceptos tanto del diagnóstico como del tratamiento. Pese a ello, actualmente existen consideraciones sobre el manejo de fracturas maleolares sin consenso. Esta revisión pretende actualizar conceptos sobre el estudio y manejo de las fracturas de tobillo. Serán discutidos los conceptos de estabilidad, estudios radiológicos, uso de tomografía axial computarizada, manejo de lesiones ligamentarias asociadas (ligamento deltoideo y sindesmosis) y manejo de fracturas del maléolo posterior. Se planteará la opinión de los autores y la evidencia en la literatura para cada pregunta propuesta.

Complications after Metatarsal Osteotomies for Hallux Valgus: Malunion, Nonunion, Avascular Necrosis, and Metatarsophalangeal Osteoarthritis.

Avascular necrosis (AVN), nonunion, malunion, and metatarsophalangeal (MTP) osteoarthritis following hallux valgus osteotomies, as well as pathophysiology, diagnosis, prevention strategies, and treatment are discussed in this article. AVN and nonunion are very infrequent, and they can be effectively prevented taking into consideration local anatomy preservation, biomechanics, and patient comorbidities. Shortening, elevation, plantarflexion, varus/valgus, and rotational of the first metatarsal are the most common types of malunion. They can lead to pain, stiffness, deformity recurrence, and transfer metatarsalgia. MTP osteoarthritis can develop after metatarsal malunion or AVN. Treatment options include cheilectomy, osteotomies to correct malunions, and MTP arthrodesis.

A New Classification System for Pilon Fractures Based on CT Scan: An Independent Interobserver and Intraobserver Agreement Evaluation.

BACKGROUND DATA: A new pilon fracture classification system based on CT scan data was recently published, showing almost perfect interobserver and intraobserver agreement among the authors who developed it. However, an independent assessment has not been done. OBJECTIVE: To do an independent agreement evaluation of the new pilon fracture classification system with physicians with different levels of expertise in the management of pilon fractures. METHODS: Seventy-one cases of acute pilon fracture were retrospectively collected. Fractures were classified by six evaluators (three foot and ankle surgeons and three orthopaedic surgery residents) using CT scans according to the morphological grading of the new pilon fracture classification system developed by Leonetti et al. Cases were presented to the same evaluators in a random sequence after a 6-week interval to determine intraobserver agreement. The kappa coefficient (κ) was used to determine agreement among evaluators. RESULTS: The interobserver agreement was substantial regarding the main fracture type (I, II, III, or IV), with an overall κ value of 0.69 (0.65 to 0.72). When including the II and III subtypes, the overall agreement was still substantial, with a κ value of 0.61 (95% confidence interval: 0.58 to 0.64). The intraobserver agreement was substantial when considering the main fracture categories (I, II, III, or IV), with a κ value of 0.78 (confidence interval: 0.72 to 0.84), and full agreement at the type level was observed in 76% (324/426) of evaluations. There was no notable difference between the foot and ankle surgeons and orthopaedic surgery residents in the interobserver and intraobserver agreement. CONCLUSION: The new classification system demonstrated substantial interobserver and intraobserver agreement between evaluators with different levels of expertise in the management of pilon fractures. Prospective studies should be done to evaluate its prognostic value and utility in clinical practice.

Acute Deltoid Ligament Repair in Ankle Fractures.

There is no consensus on whether the deltoid ligament must be repaired in ankle fractures. Recent studies have shown better early radiologic results when the deltoid ligament is repaired, but no differences in long term functional outcomes. However, there is evidence suggesting that patients with high fibular fractures or injuries with concomitant syndesmotic instability may benefit from repair. The authors recommend repairing the deltoid ligament complex in bimalleolar equivalent fractures associated with syndesmotic or gross multiligamentous instability as well as in heavier patients with greater mechanical requirements.

How to Identify Unstable Lisfranc Injuries? Review of Diagnostic Strategies and Algorithm Proposal.

"Misdiagnosed Lisfranc injuries can be as high as 50%, leading to chronic pain, functional impairment, and posttraumatic arthritis. Subtle or incomplete lesions are the most problematic group for an adequate diagnosis. Conventional non-weight-bearing radiographs can overlook up to 30% of unstable cases. Abduction stress radiographs and anteroposterior monopodial comparative weight-bearing radiographic views are very useful to identify instability. Computed tomography gives detailed information about fracture patterns and comminution. MRI can predict instability but it is expensive and not readily available in the acute setting."

[Arthroscopic treatment of pigmented villonodular synovitis of the ankle: a clinical case report and review]. / Tratamiento artroscópico de sinovitis villonodular pigmentada de tobillo: reporte de caso y revisión de literatura.

Pigmented villonodular synovitis is a benign tumor of synovial tissue with a very low incidence. Ankle location is even less frequent. Early diagnosis and management are required to avoid irreversible functional and mechanical sequelae. The clinical presentation starts with edema or joint effusion and may progress with pain and advanced joint degenerative changes. Pigmented villonodular synovitis can be focal or diffuse, the latter being the type with the worst prognosis. When suspected, magnetic resonance imaging is performed, and the diagnosis confirmed with a biopsy in which synovial inflammatory tissue with hemosiderin deposits is observed. An open or arthroscopic synovectomy is preferred over surgical management. Recurrence is up to 40%, which is why biological coadjutant therapies and radiotherapy are described. This article presents the case of a 30-year-old man who presented with pain and claudication of the left ankle; the imaging study findings were compatible with diffuse pigmented villonodular synovitis of the ankle with extension to the subtalar joint, leading to arthroscopy for treatment and biopsy. This case report illustrates the results with this patient and a literature review of the subject.

La sinovitis villonodular pigmentada es un tumor benigno del tejido sinovial de muy baja incidencia. El compromiso de tobillo es aún menos frecuente. Se requiere diagnóstico y manejo precoz para evitar secuelas funcionales y mecánicas irreversibles. Se manifiesta inicialmente con aumento de volumen de partes blandas, edema o derrame articular y puede evolucionar con dolor progresivo y daño articular avanzado. Existe una forma focal y una difusa, siendo esta última la de peor pronóstico. El examen diagnóstico de elección es la resonancia magnética, confirmándose por biopsia en la que se observa tejido sinovial inflamatorio con depósitos de hemosiderina. El tratamiento es quirúrgico y consiste en sinovectomía abierta o artroscópica. La recurrencia es de hasta un 40%, por lo que están descritas terapias coadyuvantes biológicas y radioterapia. Este artículo expone el caso de un hombre de 30 años que consulta por dolor y claudicación del tobillo izquierdo, encontrándose en el estudio imagenológico (resonancia magnética) hallazgos compatibles con sinovitis villonodular pigmentada difusa del tobillo, con extensión a la articulación subtalar, por lo que se realiza artroscopía para tratamiento y biopsia. En este reporte de caso se ilustran los resultados con este paciente y una revisión bibliográfica del tema.

Midfoot arthrodesis following multi-joint stabilization with a novel hybrid plating system.

BACKGROUND: Several methods for fixation have been described for midfoot arthrodesis. Multi-joint arthrodesis at this level can be challenging because of bone loss and deformity, making it difficult to obtain a stable construct. We present the results of a novel hybrid plating system that incorporates locked and non-locked compression screws for multi-joint arthrodesis of the midfoot. METHOD: A retrospective multicenter review of patients undergoing multi-joint arthrodesis with hybrid plating of the midfoot was performed to evaluate the time to radiographic arthrodesis. Hybrid plating was defined as a construct that incorporates locked and non-locked compression screws. Neuropathy was the only exclusion criteria. Radiographic arthrodesis was defined as bridging bone on one of the three standard foot radiographs in the absence of a joint gap on the other views, or by 50% or greater bridging bone on computed tomography. Etiology of the arthritis, presurgical comorbidities, body mass index, functional level and postoperative complications were evaluated. RESULTS: Seventy-two patients were evaluated, and arthrodesis was obtained in 67 patients at 6 weeks in 27 patients, 9 weeks in 26, 12 weeks in 11, and at 16 weeks in three. In five patients at least one of the joints were not fused at 16 weeks and were considered a nonunion. Complications were present in 12 patients (17%). CONCLUSIONS: The healing rate and time to arthrodesis compared favorably to similar published studies. Based on these results, hybrid plating was a reliable and consistent alternative for fixation in midfoot arthrodesis, especially in multi-joint disease.

Intra-articular opening medial tibial wedge osteotomy (plafond-plasty) for the treatment of intra-articular varus ankle arthritis and instability.

BACKGROUND: Although supramalleolar osteotomy with an opening medial wedge or a closing lateral wedge have been described for varus ankle deformity, these may be associated with failure due to persistence of the medial intra-articular defect, resulting in recurrent varus deformity. We report the results of a retrospective study assessing the outcome of an intra-articular opening wedge osteotomy of the distal medial tibia (plafond-plasty) for intra-articular varus ankle deformity associated with osteoarthritis and ankle instability. METHOD: The results of 19 plafond-plasties in 19 patients for correction of intra-articular varus osteoarthritis of the ankle associated with ankle instability were reviewed. Fourteen men and five women of a mean age of 47 (range, 32 to 63) years were treated. Followup ranged from 14 to 98 (mean, 59) months. RESULTS: Lateral ligament reconstruction was done at the time of the surgery in 18 out of 19 patients. The radiographic parameters including the TAS and TAL showed no statistical significant improvement when compared pre and post operatively. The varus ankle tilt deformity improved from 18 degrees preoperatively to 10 degrees postoperatively (p < 0.05). The pre- and postoperative AOFAS score improved significantly from 46 to 78, respectively (p < 0.05). Two patients underwent ankle arthrodesis at 7 and 36 months, and two patients underwent ankle replacement at 30 and 48 months following the index procedure. Of the remaining 15 patients, 14 reported stable or very stable ankles, and 15 of the 19 were either satisfied or very satisfied with the outcome of treatment. CONCLUSIONS: These results demonstrate that plafond-plasty osteotomy associated with lateral ligament reconstruction may be a suitable for patients presenting with intra-articular varus ankle osteoarthritis associated with ankle instability, providing pain relief and better function and stability in most patients.

Safety and efficacy of an E2 glycoprotein subunit vaccine produced in mammalian cells to prevent experimental infection with bovine viral diarrhoea virus in cattle.

Bovine viral diarrhea (BVD) infection caused by bovine viral diarrhea virus (BVDV), a Pestivirus of the Flaviviridae family, is an important cause of morbidity, mortality and economical losses in cattle worldwide. E2 protein is the major glycoprotein of BVDV envelope and the main target for neutralising antibodies (NAbs). Different studies on protection against BVDV infection have focused on E2, supporting its putative use in subunit vaccines. A truncated version of type 1a BVDV E2 (tE2) expressed in mammalian cells was used to formulate an experimental oleous monovalent vaccine. Immunogenicity was studied through immunisation of guinea pigs and followed by trials in cattle. Calves of 8-12 months were vaccinated, twice with a 4 week interval, with either a tE2 subunit vaccine (n = 8), a whole virus inactivated vaccine (n = 8) or left untreated as negative control group (n = 8). Four weeks after the last immunisation the animals were experimentally challenged intranasally with a non-cythopathic BVDV strain. Following challenge, BVDV was isolated from all unvaccinated animals, while 6 out of 8 animals vaccinated with tE2 showed complete virological protection indicating that the tE2 vaccine presented a similar performance to a satisfactory whole virus inactivated vaccine.

Bone block lengthening of the proximal interphalangeal joint for managing the floppy toe deformity.

The short floppy toe, an iatrogenic condition in which the digit lacks structural stability, results from excessive resection of the distal aspect of the proximal phalanx during correction of claw or hammer toe deformity. The involved toe is much shorter than the adjacent digit, which it will often overlap. Little attention has been given to the cause and treatment of the floppy toe deformity in the literature. As an iatrogenic condition, the best treatment is prevention. This article discusses the various procedures for the surgical correction of the floppy toe deformity.

Interphalangeal joint lengthening arthrodesis for the treatment of the flail toe.

BACKGROUND: Flail toe is a bothersome complication following PIP resection arthroplasty, usually as a result of excessive bone resection. Patients complain of toe instability and catching on socks or shoes. We describe a PIP joint lengthening arthrodesis using structural bone graft for treatment of this condition. MATERIALS AND METHODS: The results of 13 toe lengthening arthrodesis procedures in 13 patients were reviewed. Twelve patients were available for final followup, ranging from 6 to 70 (average, 31) months. RESULTS: Relief of instability symptoms occurred in all of the patients. The union rate was 75% (9/12 toes). Infection occurred in four patients, all treated successfully with oral antibiotics and pin removal when necessary. Two patients presented with ischemic complications in the tip of the toe which resolved spontaneously with good final results. Eleven of 12 patients were satisfied with the procedure and stated that they would do the surgery again. CONCLUSION: We believe toe lengthening arthrodesis is a good salvage operation for a flail toe following PIP resection arthroplasty.

Development and statistical validation of a guinea pig model for vaccine potency testing against Infectious Bovine Rhinothracheitis (IBR) virus.

Infectious Bovine Rhinothracheitis (IBR) caused by bovine herpesvirus 1 (BoHV-1) infection is distributed worldwide. BoHV-1 either alone or in association with other respiratory cattle pathogens causes significant economic losses to the livestock industry. The aim of this work was to validate a guinea pig model as an alternative method to the current BoHV-1 vaccine potency testing in calves. Guinea pigs were immunized with two doses of vaccine, 21 days apart and sampled at 30 days post vaccination (dpv). BoHV-1 antibody (Ab) response to vaccination in guinea pigs, measured by ELISA and virus neutralization (VN), was statistically compared to the Ab response in cattle. The guinea pig model showed a dose-response relationship to the BoVH-1 antigen concentration in the vaccine and it was able to discriminate among vaccines containing 1log(10) difference in its BoHV-1 concentration with very good repeatability and reproducibility (CV < or = 20%). A regression analysis of the Ab titers obtained in guinea pigs and bovines at 30 and 60dpv, respectively, allowed us to classify vaccines in three potency categories: "very satisfactory", "satisfactory" and "unsatisfactory". Bovines immunized with vaccines corresponding to each of these three categories were experimentally challenged with BoVH-1 virus, the level of protection, as measured by reduction of virus shedding and disease severity, correlated well with the vaccine category used. Data generated by 85 experiments, which included vaccination of calves and guinea pigs with 18 reference vaccines of known potency, 8 placebos and 18 commercial vaccines, was subjected to statistical analysis. Concordance analysis indicated almost perfect agreement between the model and the target species for Ab titers measured by ELISA and almost perfect to substantial agreement when Ab titers were measured by VN. Taken together these results indicate that the developed guinea pig model represents a novel and reliable tool to estimate batch-to-batch vaccine potency and to predict efficacy of killed BoHV-1 veterinary vaccines.