Mechanics of the foot and ankle joints during running using a multi-segment foot model compared with a single-segment model.

The primary purpose of this study was to compare the ankle joint mechanics, during the stance phase of running, computed with a multi-segment foot model (MULTI; three segments) with a traditional single segment foot model (SINGLE). Traditional ankle joint models define all bones between the ankle and metatarsophalangeal joints as a single rigid segment (SINGLE). However, this contrasts with the more complex structure and mobility of the human foot, recent studies of walking using more multiple-segment models of the human foot have highlighted the errors arising in ankle kinematics and kinetics by using an oversimplified model of the foot. This study sought to compare whether ankle joint kinematics and kinetics during running are similar when using a single segment foot model (SINGLE) and a multi-segment foot model (MULTI). Seven participants ran at 3.1 m/s while the positions of markers on the shank and foot were tracked and ground reaction forces were measured. Ankle joint kinematics, resultant joint moments, joint work, and instantaneous joint power were determined using both the SINGLE and MULTI models. Differences between the two models across the entire stance phase were tested using statistical parametric mapping. During the stance phase, MULTI produced ankle joint angles that were typically closer to neutral and angular velocities that were reduced compared with SINGLE. Instantaneous joint power (p<0.001) and joint work (p<0.001) during late stance were also reduced in MULTI compared with SINGLE demonstrating the importance of foot model topology in analyses of the ankle joint during running. This study has highlighted that considering the foot as a rigid segment from ankle to MTP joint produces poor estimates of the ankle joint kinematics and kinetics, which has important implications for understanding the role of the ankle joint in running.

Relationship between arthritis of the second and third tarsometatarsal joints and incongruity of the first tarsometatarsal joint in patients with hallux valgus.

OBJECTIVES: Hallux valgus is associated with tarsometatarsal arthritis; its pathophysiology remains unknown. Therefore, we aimed to elucidate the relationship between arthritis of the second and third tarsometatarsal joints and incongruity of the first tarsometatarsal joint in the sagittal plane. METHODS: Forty-three patients (64 feet) with hallux valgus who underwent surgery at University Hospital Kyoto Prefectural University of Medicine were included and divided into two groups: control (without second and third tarsometatarsal joint degeneration) and osteoarthritis (with second and third tarsometatarsal joint degeneration). Intergroup comparisons of the incongruity of the first tarsometatarsal joint in the sagittal plane, age, body mass index, hallux valgus angle, first-second intermetatarsal angle, metatarsus adductus angle, Meary's angle, and calcaneal pitch angle were performed. RESULTS: The proportion of patients with incongruity of the first tarsometatarsal joint was significantly higher in the osteoarthritis group than in the control group. Logistic regression analysis identified incongruity of the first tarsometatarsal joint and metatarsus adductus angle as significant related factors for arthritis of the second and third tarsometatarsal joints. CONCLUSIONS: Incongruity of the first tarsometatarsal joint in the sagittal plane was involved in the development of arthritis of the second and third tarsometatarsal joints in patients with hallux valgus.

Structural Foot Characteristics in People With Midfoot Osteoarthritis: Cross-Sectional Findings From the Clinical Assessment Study of the Foot.

OBJECTIVE: This study compared radiographic measures of foot structure between people with and without symptomatic radiographic midfoot osteoarthritis (OA). METHODS: This was a cross-sectional study of adults aged 50 years and older registered with four UK general practices who reported foot pain in the past year. Bilateral weightbearing dorsoplantar and lateral radiographs were obtained. Symptomatic radiographic midfoot OA was defined as midfoot pain in the last 4 weeks, combined with radiographic OA in one or more midfoot joints (first cuneometatarsal, second cuneometatarsal, navicular-first cuneiform, and talonavicular). Midfoot OA cases were matched 1:1 for sex and age to controls with a 5-year age tolerance. Eleven radiographic measures were extracted and compared between the groups using independent sample t-tests and effect sizes (Cohen's d). RESULTS: We identified 63 midfoot OA cases (mean ± SD age was 66.8 ± 8.0 years, with 32 male and 31 female participants) and matched these to 63 controls (mean ± SD age was 65.9 ± 7.8 years). There were no differences in metatarsal lengths between the groups. However, those with midfoot OA had a higher calcaneal-first metatarsal angle (d = 0.43, small effect size, P = 0.018) and lower calcaneal inclination angle (d = 0.46, small effect size, P = 0.011) compared with controls. CONCLUSIONS: People with midfoot OA have a flatter foot posture compared with controls. Although caution is required when inferring causation from cross-sectional data, these findings are consistent with a pathomechanical pathway linking foot structure to the development of midfoot OA. Prospective studies are required to determine the temporal relationships between foot structure, function, and the development of this common and disabling condition.

Changes in Relative Work of the Lower Extremity and Distal Foot Joints After Total Ankle Replacement: An Exploratory Study.

Ankle osteoarthritis does not only led to lower ankle power generation, but also results in compensatory gait mechanics at the hip and Chopart joints. Much of previous work explored the relative work distribution after total ankle replacement (TAR) either across the lower extremity joints where the foot was modelled as a single rigid unit or across the intrinsic foot joints without considering the more proximal lower limb joints. Therefore, this study aims, for the first time, to combine 3D kinetic lower limb and foot models together to assess changes in the relative joint work distribution across the foot and lower limb joints during level walking before and after patients undergo TAR. We included both patients and healthy control subjects. All patients underwent a three-dimensional gait analysis before and after surgery. Kinetic lower limb and multi-segment foot models were used to quantify all inter-segmental joint works and their relative contributions to the total lower limb work. Patients demonstrated a significant increase in the relative ankle positive joint work contribution and a significant decrease in the relative Chopart positive joint work contribution after TAR. Furthermore, there exists a large effect toward decreases in the relative contribution of the hip negative joint work after TAR. In conclusion, this study seems to corroborate the theoretical rationale that TAR reduces the compensatory strategy in the Chopart and hip joints in patients suffering from end-stage ankle osteoarthritis.

The Posttraumatic Tarsometatarsal Joints.

Tarsometatarsal joint injuries can be painful and debilitating and are most commonly due to direct or indirect trauma. Posttraumatic arthritis is a well-known long-term complication, with incidence as high as 58%. Conservative treatment options include shoe modifications, orthotic inserts, topical or oral anti-inflammatories, and intra-articular corticosteroid injections. There are various joint prep and fixation techniques reported in the literature, many with positive clinical and radiographic outcomes. This article discusses nonoperative and operative management of posttraumatic tarsometatarsal joint arthritis, reviews available literature, and includes the authors' tips and techniques.

Foot Sole Contact Forces vs. Ground Contact Forces to Obtain Foot Joint Moments for In-Shoe Gait-A Preliminary Study.

In-shoe models are required to extend the clinical application of current multisegment kinetic models of the bare foot to study the effect of foot orthoses. Work to date has only addressed marker placement for reliable kinematic analyses. The purpose of this study is to address the difficulties of recording contact forces with available sensors. Ten participants walked 5 times wearing two different types of footwear by stepping on a pressure platform (ground contact forces) while wearing in-shoe pressure sensors (foot sole contact forces). Pressure data were segmented by considering contact cells' anteroposterior location, and were used to compute 3D moments at foot joints. The mean values and 95% confidence intervals were plotted for each device per shoe condition. The peak values and times of forces and moments were computed per participant and trial under each condition, and were compared using mixed-effect tests. Test-retest reliability was analyzed by means of intraclass correlation coefficients. The curve profiles from both devices were similar, with higher joint moments for the instrumented insoles at the metatarsophalangeal joint (~26%), which were lower at the ankle (~8%) and midtarsal (~15%) joints, although the differences were nonsignificant. Not considering frictional forces resulted in ~20% lower peaks at the ankle moments compared to previous studies, which employed force plates. The device affected both shoe conditions in the same way, which suggests the interchangeability of measuring joint moments with one or the other device. This hypothesis was reinforced by the intraclass correlation coefficients, which were higher for the peak values, although only moderate-to-good. In short, both considered alternatives have drawbacks. Only the instrumented in-soles provided direct information about foot contact forces, but it was incomplete (evidenced by the difference in ankle moments between devices). However, recording ground reaction forces offers the advantage of enabling the consideration of contact friction forces (using force plates in series, or combining a pressure platform and a force plate to estimate friction forces and torque), which are less invasive than instrumented insoles (which may affect subjects' gait).

The Role of First Tarsometatarsal Joint Morphology and Instability in the Etiology of Hallux Valgus: A Case-Control Study.

BACKGROUND: The morphology of foot joints is widely accepted as a significant factor in the development of various foot disorders. Nevertheless, the role of the first tarsometatarsal joint (TMT1) morphology in hallux valgus (HV) remains unclear, and its impact on TMT1 instability has not been fully explored. This study aimed to investigate the TMT1 morphology and its potential correlation with HV and TMT1 instability. METHODS: Weightbearing computed tomography (WBCT) scans of 82 consecutive feet with HV and 79 controls were reviewed in this case-control study. Three-dimensional (3D) models of TMT1 were constructed using Mimics software and WBCT scans. The height of the TMT1 facet (FH) and the superior, middle, and inferior facet width (SFW, MFW, and IFW) were measured on anteroposterior view of the first metatarsal base. On the lateral view, the inferior lateral facet height and angle (ILFH and ILFA) were measured. TMT1 instability was evaluated using the TMT1 angle. RESULTS: Compared with the control group, the HV group had a significantly wider MFW (9.9 mm in HV, 8.7 mm in control), lower ILFH (1.7 mm in HV, 2.5 mm in control), smaller ILFA (16.3 degrees in HV, 24.5 degrees in control), and larger TMT1 angle (1.9 degrees in HV, 0.9 degrees in control) (all P < .05). No significant differences were found between the 2 groups in FH, SFW, and IFW (all P > .05). The study identified 4 types of TMT1 morphology: continuous-flat, separated-flat, continuous-protruded, and separated-protruded. The continuous-flat type possessed significantly larger HVA, IMA, and TMT1 angles compared with other types (all P < .001). CONCLUSION: This study indicates a potential association between TMT1 morphology and the severity of HV and identifies 4 TMT1 types. Notably, the continuous-flat type is found to be associated with more severe HV and TMT1 instability. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Kinetic coupling in distal foot joints during walking.

BACKGROUND: Kinematic coupling between the first metatarsophalangeal (MTP) and midtarsal joints is evident during gait and other movement tasks, however kinetic foot coupling during walking has not been examined. Furthermore, contributing factors to foot coupling are still unclear. Therefore, the purpose of this study was to investigate kinematic and kinetic coupling within the foot by restricting MTP motion during overground walking. We hypothesized that when the MTP joint was prevented from fully extending, the midtarsal joint would achieve less peak motion and generate less positive work compared to walking with normal MTP motion. METHODS: Twenty-six individuals participated in this randomized cross-over study. Using motion capture to track motion, participants walked at 1.3 m/s while wearing a brace that restricted MTP motion in a neutral (BR_NT) or extended (BR_EX) position. Additionally, participants walked while wearing the brace in a freely moveable setting (BR_UN) and with no brace (CON). A pressure/shear sensing device was used to capture forces under each foot segment. During stance, peak joint motion and work were calculated for the MTP and midtarsal joints using inverse dynamics. A series of ANOVAs and Holm post hoc tests were performed for all metrics (alpha = 0.05). RESULTS: The brace successfully decreased peak MTP motion by 19% compared to BR_UN and CON. This was coupled with 9.8% less midtarsal motion. Kinetically, the work absorbed by the MTP joint (26-51%) and generated by the midtarsal joint (30-38%) were both less in BR_EX and BR_NT compared to BR_UN. CONCLUSION: Implications and sources of coupling between the MTP and midtarsal joints are discussed within the context of center of pressure shifts and changes to segmental foot forces. Our results suggest that interventions aimed at modulating MTP negative work (such as footwear or assistive device design) should not ignore the midtarsal joint.

Morphologic analysis of the 1st and 2nd tarsometatarsal joint articular surfaces.

Tarsometatarsal joint arthrodesis is used to treat a variety of injuries and deformities in the midfoot. However, the surgical technique has not been optimized, in part due to limited knowledge of morphologic features and variation in the related joints. Previous research has relied primarily on dissection-based anatomical analysis, but quantitative imaging may allow for a more sophisticated description of this complex. Here, we used quantitative micro-CT imaging to examine dimensions, distance maps, and curvature of the four articular surfaces in the first and second tarsometatarsal joints. Image segmentation, articular surface identification, and anatomic coordinate systems were all done with semi or fully automatic methods, and distance and size measurements were all taken utilizing these anatomic planes. Surface curvature was studied using Gaussian curvature and a newly defined measure of curvature similarity on the whole joint and on four subregions of each surface. These data show larger articular surfaces on the cuneiforms, rather than metatarsals, and define the generally tall and narrow articular surfaces seen in these joints. Curvature analysis shows minimally curved opposing convex surfaces. Our results are valuable for furthering knowledge of surgical anatomy in this poorly understood region of the foot.

Nonoperative management of lisfranc injuries - A systematic review of outcomes.

BACKGROUND: Historically, most Lisfranc injuries have been considered to be unstable and treated with surgical intervention. However, with better access to cross-sectional imaging, stable injury patterns are starting to be recognised. The aims of the current study were to perform a systematic review of outcomes of Lisfranc injuries treated non-operatively. METHODS: A literature review was performed of studies reporting nonoperative management of Lisfranc injuries (PROSPERO registered and following PRISMA guidelines). Following exclusions, 8 papers were identified: 1 prospective and 7 retrospective studies. A total of 220 patients were studied with a mean age of 39.8 years and a mean follow-up of 4.3 years. Outcomes included function, displacement, and rates of surgery. RESULTS: High heterogeneity was observed with variable outcomes. Four papers reported good outcomes, with adjusted functional scores ranging from 82.6 to 100 (out of 100). However, one study reported late displacement in 54 % of patients. Rates of secondary osteoarthritis ranged from 5 % to 38 %. Rates of surgical intervention were as high as 56 %. Several studies compared operative to non-operative treatment, reporting superior outcomes with surgery. Those injuries with no displacement on CT, measured at the medial cuneiform-second metatarsal had the best outcomes. CONCLUSION: Reported outcomes following nonoperative treatment of Lisfranc injuries vary widely, including high rates of conversion to surgery. In contrast, some studies have reported excellent functional outcomes. CT seems to be an important diagnostic tool in defining a stable injury. Due to limited data and lack of a clear definition of a stable injury or treatment protocol, prospective research is needed to determine which Lisfranc injuries can be safely treated nonoperatively.

Addressing Medial Column Instability in Flatfoot Deformity.

A stable medial column is important to the normal function of the foot and ankle. Medial column instability and forefoot varus can result in compensatory hindfoot motion leading to stress along the medial soft-tissue structures. Medial column stabilization should therefore be considered when (1) forefoot varus deformity is identified following hindfoot realignment; (2) pronounced medial column instability is present, even in the absence of forefoot varus; and (3) when degenerative changes are present within the medial column articulations. Common surgical procedures include arthrodesis of the talonavicular joint, naviculocuneiform joint, and first tarsometatarsal joint, as well as osteotomy of the medial cuneiform (Cotton osteotomy).

Naviculocuneiform Arthrodesis for Treatment of Adult-Acquired Flatfoot Deformity.

The adult-acquired flatfoot is a complex multiplanar deformity that requires the foot and ankle surgeon to balance soft tissue, correct hindfoot valgus, and address instability of the medial column. The naviculocuneiform joint is historically underappreciated in regard to its involvement in medial column instability relative to the talonavicular and tarsometatarsal joints. Proper clinical and radiographic evaluation of the medial column, specifically evaluating for deformity at each medial column joint, will allow the surgeon to ensure correction of deformity and decrease the recurrence of instability or failure of the reconstruction.

Early results and complication rate of the LapiCotton procedure in the treatment of medial longitudinal arch collapse: a prospective cohort study.

INTRODUCTION: Instability/collapse of the medial column has been associated with many conditions, particularly progressive collapsing foot deformity (PCFD), hallux valgus (HV), and midfoot arthritis (MA). Restoration of first ray length and sagittal plane alignment to restore the foot tripod is essential when treating these deformities. This study aimed to assess early results, healing, and complication rate of a distraction dorsal opening plantarflexion wedge allograft first tarsometatarsal joint fusion (LapiCotton Procedure) in patients with collapse/instability of the medial column. METHODS: In this prospective cohort study, we included PCFD, HV, and MA patients that underwent a LapiCotton procedure. Fusion site healing was defined by > 50% bone bridging in both interfaces between allograft wedge and host bone using weight-bearing computed tomography (WBCT) after 3 months. First ray collapse radiographic correction and minor and major complications (deep dehiscence, deep infection, and reoperation) were assessed. RESULTS: A total of 22 patients (22 feet) were included (11 PCFD, 6 MA, and 5 of HV patients). Mean follow-up was 5.9 months (range 3-12) and median allograft size was 8 mm (range 5-19 mm). Bone healing was observed in 91% of cases. Two minor complications (9%, both superficial dehiscence) and one major complication (4.5%, deep infection) were observed. Statistically significant improvement of the sagittal plane talus-first metatarsal angle was observed, with mean improvement of 9.4° (95% CI 6.7-12.1°; p < 0.0001). CONCLUSION: In this prospective cohort study of 22 patients treated with the LapiCotton procedure for medial longitudinal arch collapse/instability, we observed a low complication rate (9% minor, 4.5% major), high healing rate after 3 months (91%), one clinically stable radiographic non-union (4.5%) and one unstable non-union (4.5%) needing reoperation. Our results demonstrate promising initial results for LapiCotton technique in treating collapse of the medial longitudinal arch in patients with PCFD, MA and HV deformities. Long-term results are needed to confirm these promising results. LEVEL OF EVIDENCE: Level II, prospective cohort study.

The Assessment of the Quality of Life in Patients with Rheumatoid Foot.

BACKGROUND: The negative effects of rheumatoid arthritis (RA) are multi-dimensional. Foot deformities lead to disability, pain, and impaired quality of life. OBJECTIVE: Identifying the difficulties in functioning rheumatoid foot and assessing the quality of life in this aspect. MATERIALS AND METHODS: The material included 50 patients of Rheumatology Policlinic of the Central Clinical Hospital of Interior Affairs in Warsaw and a matched control group of 50 individuals without RA. The degree of foot joint damage was assessed using the Manchester scale, lower limb movement and quality of life using the American Orthopedic Foot and Ankle Society Score and HAQ. RESULTS: The duration of symptoms was 16.0 ± 8.9 years. High activity of RA measured by the DAS was observed in 20% of patients, moderate in 26%, and low in 54%. The most common foot deformities were: hammer toes (82%), longitudinal flat feet (74%), and hyperkeratosis (56%). The least frequent were: stiff toe (38%) and overlapping fingers (28%). In the RA group, the outcomes of the FAOS questionnaire were statistically significantly worse than in the control group in all categories (p<0.001). The worst-rated domain was the sport and recreation subscale (median 55.0), the best daily activity (median 86.8). The strongest relationship was demonstrated between the FAOS and HAQ indices. Spearman's HAQ correlation coefficient with the ADL subscale was r=-0.85, p<0.001; with the QOL, sport/recreation and pain subscales moderate, it was r=-0.72; r= 0.71, p <0.001. CONCLUSION: Lower limb movement function and quality of life are worse in RA patients; pain accompanies climbing and descending stairs; running and jumping require effort.

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.

Differences in the coordination and its variability among foot joints during running in neutral foot and flatfoot.

Flatfoot is a well-known foot deformity, with a prevalence of 11.2%-29.0% among adults. Running injuries can occur in individuals with flatfoot; however, the underlying mechanism remains unknown. We investigated the coordination pattern and variability among foot joints while running by comparing participants with neutral foot and with flatfoot. Participants with neutral foot (n = 15) and flatfoot (n = 15) were asked to run at their preferred speed. Using the modified vector coding technique, the coupling angle between the foot joints, representing interjoint coordination, was calculated and categorized into four coordination patterns. The standard deviation of the coupling angle was computed to measure the coordination variability during the stance phase. There were no differences in the spatiotemporal parameters (speed, step length, and cadence) between the groups. In the sagittal rearfoot and sagittal midfoot coordination patterns, the flatfoot group showed a significantly greater proportion of anti-phase with proximal dominancy and a lower proportion of in-phase with proximal dominancy than the neutral foot group during early stance. Coordination variabilities between the sagittal rearfoot and sagittal midfoot (midstance), between the sagittal midfoot and sagittal forefoot (early stance), and between the frontal rearfoot and sagittal midfoot (midstance) were greater in the flatfoot group than in the neutral foot group. This may explain why those with flatfoot are likely to experience running injuries.

Does temporary bridge plate fixation preserve joint motion after an unstable Lisfranc injury?

BACKGROUND: Recently, temporary bridge plate fixation has gained popularity in the treatment of unstable Lisfranc injuries. The technique aims to reduce the risk of posttraumatic osteoarthritis, and after plate removal, the goal is to regain joint mobility. Here we explore marker-based radiostereometric analysis (RSA) to measure motion in the 1st tarsometatarsal (TMT) joint and asses the radiological outcome in patients treated with this surgical technique. METHOD: Ten patients with an unstable Lisfranc injury were included. All were treated with a dorsal bridge plate over the 1st TMT joint and primary arthrodesis of the 2nd and 3rd TMT joints. The plate was removed four months postoperatively. Non- and weight-bearing RSA images were obtained one and five years postinjury to assess joint mobility and signs of osteoarthritis. RESULTS: Detectable 1st TMT joint motion was observed in 2/10 patients after one year, and 6/9 patients after five years. At the final follow-up, mean 1st TMT dorsiflexion was 2.0°. Radiologically, the incidence of posttraumatic osteoarthritis was present in 4/10 patients after one year, and 5/9 patients after five years. All patients had observed TMT joint stability throughout the follow-up period. CONCLUSION: Preservation of joint motion can be achieved with a temporary bridge plate fixation over the 1st TMT joint. TYPE OF STUDY/LEVEL OF EVIDENCE: Prospective cohort study/Therapeutically level IV.

Luxación medial y plantar del hueso navicular asociada a fractura-subluxación calcaneocuboidea. Presentación de un caso / Medial and plantar dislocation of the navicular bone associated with a calcaneocuboid fracture-subluxation. Case report

Las luxaciones del escafoides aisladas y sin fractura son poco frecuentes. Por lo general, se presentan asociadas a fracturas del escafoides o a diversos patrones de lesión de la columna lateral. Presentamos el caso de un paciente con luxación medial y plantar del hueso navicular y fractura conminuta del proceso anterior del calcáneo y subluxación calcaneocuboidea. En el Servicio de Urgencia, se procedió a la reducción cerrada y la estabilización con agujas de Kirschner y, como tratamiento diferido, se colocaron placas en puente astragalonaviculo-cuneiforme y calcaneocuboidea de 2,0 mm, en forma transitoria, y el material de osteosíntesis se retiró a los 5 meses. El puntaje de la escala de la AOFAS fue excelente al año de seguimiento. Conclusiones: Es necesario llegar a un diagnóstico adecuado descartando lesiones de la columna lateral y reducir esta lesión en la atención de urgencia. La estabilización con placas en puente es una opción válida que podría evitar la pérdida de la reducción que se observa al retirar los clavos de Kirschner y permite una carga precoz. Nivel de Evidencia: IV

Isolated navicular dislocations are unusual. They are frequently associated with navicular fractures or diverse patterns of lateral column injuries. We report a case of a patient with medial and plantar navicular dislocation with a comminuted intra-articular fracture of the anterior process of the calcaneus and associated subluxation at the calcaneocuboid joint. The patient underwent closed reduction and Kirschner wire stabilization in the Emergency Service. As part of the deferred treatment, talonavicular-cuneiform and calcaneocuboid 2.0 mm bridge plates were temporarily placed and osteosynthesis material was removed 5 months later. The AO-FAS score was excellent in the one-year follow-up. Conclusion: An accurate diagnosis, ruling out lateral column injuries, should be done in the Emergency Service. Bridge plate stabilization is a valid option to prevent loss of reduction, which is observed when removing Kirschner wires, allowing early weight-bearing. Level of Evidence: IV

Seguridad de los portales para la reparación endoscópica del ligamento calcaneonavicular: estudio cadavérico / Endoscopic Spring ligament repair. Anatomic evaluation of portal safety

Introducción: La lesión del ligamento calcaneonavicular ha sido descrita como una de las causas de la deformidad en el pie plano del adulto. El objetivo de este artículo es describir portales modificados para el diagnóstico y la reparación endoscópica de las lesiones del fascículo superomedial del ligamento calcaneonavicular y evaluar la seguridad de los portales utilizados. Materiales y Métodos:Se llevó a cabo un estudio cadavérico con seis preparados reproduciendo una lesión del fascículo superomedial del ligamento calcaneonavicular con una punta de corte de radiofrecuencia y la posterior reparación endoscópica. Se crearon dos portales modificados para el abordaje. Luego se procedió a la disección anatómica para evaluar la seguridad de los portales en relación con las estructuras anatómicas. El primer portal se realiza inmediatamente proximal a una línea trazada desde la punta del maléolo medial dirigida al centro del talón, el segundo portal se emplaza 0,5 cm proximal a la inserción del tendón tibial posterior en el escafoides por transiluminación. Si es necesario, se coloca un portal accesorio inmediatamente dorsal al tendón tibial posterior a mitad de camino entre los dos portales antes descritos. Resultados:En todos los casos, fue posible la reparación del ligamento con el procedimiento endoscópico. En la disección anatómica de los portales, se observó una distancia promedio a las estructuras vasculonerviosas de 11,83 mm del portal proximal y de 9,66 mm del portal distal. Conclusión: Los portales modificados son seguros y permiten la visualización directa del haz superomedial del ligamento calcaneonavicular y su reparación endoscópica. Nivel de Evidencia: IV

Introduction: Calcaneonavicular ligament injury has been described as a cause of adult flat foot deformity. The objective of this study is to describe modified portals for the diagnosis and treatment of injuries to the superomedial bundle of the calcaneonavicular ligament and to evaluate the safety of the portals used. Materials and Methods: We performed a cadaveric specimen study on 6 feet, where we reproduced a lesion of the superomedial bundle of the calcaneonavicular ligament with a radiofrequency ablation device and repaired it endoscopically. Two modified portals were created for the approach and an anatomical dissection was performed to assess the safety of the portals in relation to the anatomical structures. The first portal was placed immediately proximal to a line drawn from the tip of the medial malleolus toward the center of the heel; the second portal was placed 0.5 cm proximal to the posterior tibial tendon insertion into the navicular bone, guided by transillumination. If needed, an accessory portal was placed halfway between the two previously described portals immediately dorsal to the posterior tibial tendon. Results:In all cases, ligament repair was achieved with the endoscopic procedure. In the anatomical dissection of the portals, we observed an average distance of 11.83 mm from the proximal portal and 9.66 mm from the distal portal to neurovascular structures. Conclusion:Modified portals are safe and allow direct visualization of the superomedial bundle of the calcaneonavicular ligament to perform endoscopic repair. Level of Evidence: IV