Metatarsalgia, characterized by forefoot pain, is frequent and is primarily due to foot static disorders. Initial evaluation with weight-bearing radiographs is essential, allowing precise analysis of the architecture of the foot. Ultrasound is useful for soft tissue and tendon examination and provides the best clinical correlation. Computed Tomography provides detailed bone assessment and is helpful for pre-operative planning. Magnetic Resonance Imaging is the gold standard modality, offering superior soft tissue contrast. The common causes of metatarsalgia include hallux pathologies (hallux valgus, hallux rigidus, and sesamoid issues), bursitis (intermetatarsal and subcapitellar), Morton's neuroma, second ray syndrome, stress fractures, and systemic pathologies affecting the foot. Combining clinical and imaging data is crucial for accurate diagnosis and effective management of metatarsalgia. Post-traumatic causes of metatarsalgia are beyond the scope of this article and will not be described. CRITICAL RELEVANCE STATEMENT: Metatarsalgia, the pain of the forefoot, necessitates accurate imaging for diagnosis and management. This review critically assesses imaging techniques and diagnostic approaches, aiming to enhance radiological practice and support effective therapeutic decision-making. KEY POINTS: Metatarsalgia commonly results from foot static disorders, requiring weight-bearing radiographs for assessment. MRI is often the gold standard examination, but ultrasound is complementary, allowing for a radioclinical approach with dynamic examinations. The radiologist is crucial in diagnosing metatarsalgia, providing essential imaging, and guiding treatment.

The first metatarsophalangeal (MTP) joint plays a crucial role in foot biomechanics, particularly in weight-bearing activities such as walking and running. It is frequently affected by conditions like hallux valgus (HV) and hallux rigidus, with HV impacting approximately 23%-35% of the population. This narrative review explores the embryology, anatomy, and biomechanics of the first MTP joint (MTPJ), highlighting its significance in maintaining foot stability and function. A comprehensive literature search was conducted using PubMed, Scopus, and Google Scholar, analyzing 50 relevant studies, including 12 clinical trials. The joint's complex structure and mechanical demands make it susceptible to degenerative and structural disorders. Studies indicate that 25%-40% of individuals with HV experience significant pain and functional impairment, affecting mobility and quality of life. Biomechanical stress, abnormal gait patterns, and joint instability contribute to disease progression. Understanding the anatomical and biomechanical properties of the first MTPJ is essential for improving diagnostic and therapeutic approaches. Emerging surgical techniques, such as osteotomy and joint resurfacing, show promise in reducing recurrence rates and enhancing long-term outcomes. Further research is needed to refine minimally invasive interventions and optimize treatment strategies for first MTPJ disorders.

BackgroundThe capsuloligamentous complex injury of the first metatarsophalangeal joint (MTPJ) is a common cause of turf toe.PurposeTo investigate whether high-resolution 3 T magnetic resonance imaging (MRI) could demonstrate all the normal anatomic structures and the MR features of the capsuloligamentous complex injury of the first MTPJ, and to evaluate the diagnostic performance of MRI in the diagnosis of the capsuloligamentous complex injuries of the first MTPJ.Material and MethodsA total of 115 feet were included in this study, including 48 feet from 24 healthy volunteers and 67 feet from 67 patients with the capsuloligamentous complex of the first MTPJ injuries. All feet had MRI examination. The MRI features of the capsuloligamentous complex of the first MTPJ of the volunteers and patients were analyzed. Diagnostic sensitivity, specificity, and accuracy of MRI were calculated using the surgery as the standard of reference. The inter-observer agreement was assessed using kappa analysis.ResultsThe central portion of the plantar plate and ligament injury manifested as discontinuity, with an indistinct appearance with hyperintense signal within the involved structures. The sensitivities, specificities, and diagnostic accuracy value of MRI for diagnosing most structures of the capsuloligamentous complex injuries of the first MTPJ were 67%-100%, 93%-100%, and 0.82-0.99, respectively, and overall good to perfect inter-observer agreements (kappa=0.63-0.95).ConclusionHigh-resolution MRI allows adequate visualization of normal anatomic structures of the first MTPJ. The best visualized structure is sesamoid phalangeal ligament and the most frequent injury is complete tear of the medial sesamoid phalangeal ligament.

Hallux rigidus is a common degenerative condition of the hallux metatarsophalangeal joint (MTPJ) characterized by pain, swelling, stiffness, and limited range of motion with characteristic corresponding clinical, physical examination, and radiographic findings. Many historical risks factors including trauma and family history and patient factors including hallux valgus interphalangeus and inflammatory arthropathies have a well-substantiated etiologic role in the disease process. The purpose of this section is to review the normal and pathologic anatomy and biomechanics of the hallux MTPJ while providing an overview of the current understanding and remain debate regarding the disease process.

Hyperextension of the first metatarsophalangeal joint can lead to a turf toe injury of the plantar plate complex, resulting in significant morbidity for athletes. This article reviews the anatomy, pathophysiology, classification, and imaging findings of turf toe injuries. In turf toe trauma, many different structures can be injured, with the sesamoid-phalangeal ligaments the most common. Diagnosis, classification, and treatment options rely on clinical evaluation and specific magnetic resonance imaging findings. It is vital for radiologists to understand the anatomy, pathophysiology, and imaging findings of turf toe injuries to ensure an accurate diagnosis and appropriate management.

Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion.

The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations.

Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus.

Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

The first metatarsophalangeal joint (MTPJ), which includes the first metatarsal and proximal phalanx, plays a crucial role in gait and impacts the windlass mechanism. Disruptions to this mechanism are implicated in various foot pathologies. Jack's Test serves as a valuable tool for clinicians to assess the functionality of the MTPJ. Varus rearfoot wedges (VRFWs) are a common treatment employed in the management of lower limb pathologies. The impact of VRFWs on the resistance of the first MTPJ during Jack´s Test is currently unknown. This study aimed to measure the influence of VRFWs on the resistance of the first MTPJ during Jack´s Test. The secondary objective was to validate a new measurement method using a digital force gauge.

Thirty participants (17 women and 13 men) were enrolled. A digital force gauge measured the weight-bearing force needed for Jack's Test, thereby evaluating the effects of VRFWs of different angulations. The Kolmogorov-Smirnov test confirmed that the data followed a normal distribution (p > 0.05). The nonparametric Friedman test (p < 0.001) showed that there were significant differences among all VRFWs, while the Wilcoxon test (p < 0.001) showed that there were differences between barefoot conditions and 3°, 5°, and 8° VRFWs.

The use of 8° VRFWs yielded a statistically significant reduction in the passive dorsiflexion force of hallux during Jack's Test (12.51 N ± 4.12, p < 0.001).

The use of VRFWs has been observed to reduce dorsiflexion resistance in the proximal phalanx of the first MTPJ during Jack's Test. Additionally, the digital force gauge was proven to be a valid tool for conducting Jack's Test, thus offering a reliable measurement method.

Plantar vein thrombosis is a venous disorder affecting deep plantar veins that can manifest with non-specific localized pain, plantar foot pain, swelling, and sensation of fullness. Plantar veins are not routinely assessed during sonographic scans for deep venous thrombosis, which makes plantar venous thrombosis a commonly missed diagnosis. This paper provides a comprehensive review of the venous anatomy of the foot and imaging findings of plantar venous thrombosis as well as discusses the current literature on the topic and its differential diagnoses.

Hyperflexion injury to the metatarsophalangeal joint of the great toe, referred to as sand toe, can cause significant functional impairment. To our knowledge, there have been no radiological descriptions of this injury in the paediatric age group. Here, we report radiographic, sonographic and MRI findings in a male paediatric patient who sustained a sand toe injury, highlighting structural damage to the dorsomedial capsule and medial sagittal band, and discuss sand toe's favourable prognosis with conservative management.

Radiography is the appropriate initial imaging modality to assess for midfoot and forefoot pathology before turning to advanced imaging techniques. While most lesions of the mid- and forefoot can be diagnosed clinically, the exact nature and severity of the pathology is often unclear. This review addresses the use of the ultrasound, as well as the added value of magnetic resonance imaging, in diagnosing conditions of the midfoot and forefoot. Ultrasound allows a dynamic assessment as well as enabling imaging-guided interventions for diagnostic and therapeutic purposes. Practical tips for optimal examination of this area with ultrasound and magnetic resonance imaging are provided. Metatarsal stress fracture, Chopart's injury, Lisfranc injury, as well as the 1st metatarsophalangeal joint injury and lesser metatarsophalangeal plantar plate injury are injuries unique to the mid- and forefoot. The imaging anatomy of the 1st and lesser metatarsophalangeal joints is reviewed, as such knowledge is key to correctly assessing injury of these joints. Characteristic imaging features of masses commonly encountered in the mid- and forefoot, such as ganglion cyst, Morton neuroma, gouty tophus, plantar fibroma, foreign body granuloma, and leiomyoma are reviewed. The use of ultrasound and magnetic resonance imaging in assessing degenerative and inflammatory joint disorders, and in particular rheumatoid arthritis, of the mid- and forefoot region is also reviewed. In summary, when necessary, most lesions of the mid-and forefoot can be adequately assessed with ultrasound, supplemented on occasion with radiographs, computed tomography, or magnetic resonance imaging.

Determine whether MR imaging findings or demographics predict surgical management in patients with first MTP joint injuries.

Retrospective study of 161 forefoot MRs for traumatic first MTP injury (M:F 92:69, mean age 33 ± 13 yrs.). Two radiologists reviewed imaging for ligamentous, osseous, and tendinous injuries. Ligaments and tendons were graded as 0:normal, 1:sprain or strain, 2:partial tear, 3:complete tear. Osseous injuries were classified as edema, fracture, or cartilage injury. Clinical data obtained included sex, age, injury acuity, sport participation, level of sport, and treatment. Imaging findings and demographic data were assessed to determine predictive factors for surgical management. Statistics included kappa, chi-squared, Fisher's exact, and logistic regression.

Logistic regression (odds ratio [95% CI], p-value) showed that grade 2 or 3 injuries of the plantar ligamentous complex (2.87, [1.10, 7.48], p = 0.031), grade 2 or 3 injuries of the medial collateral ligament (3.24, [1.16, 9.08], p = 0.025), and participation in collegiate or professional sports (4.34 [1.64, 11.52], p = 0.003) were associated with an increased rate of surgical intervention. k = ligamentous injury (0.71-0.83), osseous trauma (0.88-0.95), and tendon injury (0.78). All other imaging findings and demographic factors were not significant predictors of surgery (p > 0.05).

Participation in collegiate or professional sports and tears of the plantar ligamentous complex or medial collateral ligament predicted surgical management in patients with first MTP trauma.

Isolated disruption of the medial collateral ligament of the great toe is rare and often misdiagnosed as turf toe. It may progress to acquired traumatic hallux valgus, often requiring operative intervention and a longer return to play. This case of a grade II medial collateral ligament injury highlights the importance of a thorough physical examination and consideration of the mechanism of injury. It demonstrates the utility of diagnostic musculoskeletal ultrasound in establishing a specific diagnosis upon initial patient presentation with great toe pain. It is an example of the use of ultrasound in guiding treatment and monitoring interval healing. In this case, differentiation of the injury from the classic "turf toe" led to proper stabilization with a toe spacer and activity modification, thus preventing progression of traumatic hallux valgus and leading to successful nonoperative treatment with full return to sport.

Level V.

Turf toe is a common injury of the hallux metatarsophalangeal (MTP) joint in athletes which is the result of hyperdorsiflexion injury. While the term turf toe has been used to describe a variety of first MTP joint injuries, the term is now typically used in imaging to describe tearing or injury to the plantar plate complex. This review article will cover normal anatomy of the first MTP joint, mechanism of injury, typical imaging findings in normal individuals on MRI and ultrasound, as well as the most common patterns of injury.

First metatarsophalangeal joint (MTP) joint osteoarthritis (OA) is prevalent, although the pathology of this condition is poorly understood. This study aimed to determine if there were differences in magnetic resonance imaging (MRI) characteristics of the first MTP joint between individuals with and without first MTP joint OA.

This cross-sectional study compared 22 participants with first MTP joint OA to 22 control participants without first MTP joint OA (matched for age, sex, and body mass index). Participants underwent MRI of their first MTP joint and osteophytes, bone marrow lesions, subchondral cysts, effusion-synovitis, joint space narrowing, and cartilage loss were documented using an atlas of first MTP joint OA. Associations of MRI characteristics with the presence of first MTP joint OA were then determined.

The presence of first MTP joint OA was associated with increased severity of osteophytes (dorsal metatarsal head, plantar metatarsal head, and dorsal proximal phalanx), bone marrow lesions (metatarsal head and proximal phalanx), cysts of the metatarsal head, effusion-synovitis (dorsal aspect), joint space narrowing (metatarsal-proximal phalanx; metatarsal-sesamoids), and cartilage loss. In contrast, there were no statistically significant associations for bone marrow lesions of the sesamoids, cysts of the proximal phalanx, or effusion-synovitis (plantar aspect).

Osteophytes, bone marrow lesions, subchondral cysts, effusion-synovitis, joint space narrowing, and cartilage loss are characteristic MRI features of first MTP joint OA. First MTP joint OA is a disease of multiple joint tissues and this has implications for the assessment and management of this condition. Key Points • First metatarsophalangeal joint osteoarthritis is a disease of multiple joint tissues. • Osteophytes, bone marrow lesions, subchondral cysts, effusion-synovitis, joint space narrowing, and cartilage loss are characteristic MRI features of first metatarsophalangeal joint osteoarthritis. • These findings have implications for the assessment and management of this condition.

A wide variety of pathologies can affect the hallux sesamoid complex of the foot, including traumatic, micro traumatic, degenerative, inflammatory, vascular, infectious, and neoplastic conditions. Symptoms are quite nonspecific, mainly related to pain in the plantar surface of the first metatarsal head. In this context, imaging is important for the etiologic diagnosis of hallux sesamoid complex pathology with implications in patient management. The hallux sesamoid complex has a complex anatomy, and pathologic processes of this region are poorly known of radiologists. Besides, some entities such as "sesamoiditis" remain poorly defined in the literature. Schematically, conditions affecting sesamoids will be divided into two major groups: intrinsic anomalies (sesamoid bone being the center of the pathologic process) and extrinsic anomalies (diseases secondarily involving sesamoid bones). Thus, in this article, after a review of anatomical key points and pathologies affecting the hallux sesamoid complex, a practical multimodality approach for the diagnosis of hallux sesamoid pathologies will be proposed.