Comparison of diagnostic performance of X‑ray, CT and MRI in patients with surgically confirmed subtle Lisfranc injuries

The present study aimed to compare the diagnostic performance of three imaging tests: X-ray, computed tomography (CT) and magnetic resonance imaging (MRI), for subtle Lisfranc injuries and three anatomical subtype injuries. The non-weight-bearing X-ray, CT and MRI imaging results of patients with subtle Lisfranc injuries from September 2013 to March 2022 were retrospectively reviewed. Subtle Lisfranc injuries and three anatomical subtypes (first, second and cuneiform rays) were diagnosed based on the surgical reports. The diagnostic performance of X-ray, CT and MRI was compared. The sensitivity (Sn), specificity (Sp), positive predictive value, negative predictive value, area under the receiver operating characteristic curve (AUC) and κ coefficient were reported. A total of 31 patients were included in the study. The correct diagnosis was made in 48.4% (15/31), 87.1% (27/31) and 96.8% (30/31) of patients by X-ray, CT and MRI, respectively. A total of 54 different anatomical injuries were found intraoperatively in all patients, with MRI and CT having high agreement (Sn, 72.2 and 87.0%; κ, 0.69 and 0.78, respectively) and X-ray having a low agreement (Sn, 29.6%; κ, 0.26) with the surgical findings. Regarding the first-ray injuries, CT had the highest Sn (76.9%), Sp (100%) and AUC (0.885) in diagnosing subtle Lisfranc injuries. MRI showed the best Sn (88.5 and 93.3%, respectively) and AUC (0.942 and 0.904, respectively) in both second and cuneiform rays. In conclusion, non-weight-bearing X-rays had poor diagnostic accuracy for subtle Lisfranc injuries and their subtypes. CT was superior to X-rays and MRI in diagnosing first-ray injuries. Although not significantly different from CT in terms of overall diagnosis, MRI was superior to X-ray and CT in diagnosing second and cuneiform-ray injuries.

Cone-Beam CT of the Extremities in Clinical Practice

Cone-beam CT (CBCT) is a promising tool with increasing applications in musculoskeletal imaging due to its ability to provide thin-section CT images of the appendicular skeleton and introduce weight bearing, which accounts for loading forces that typically interact with and affect this anatomy. CBCT devices include an x-ray source directly opposite a digital silicon detector panel that performs a single rotation around an object of interest, obtaining thin-section images. Currently, the majority of research has been focused on the utility of CBCT with foot and ankle pathologic abnormalities, due to the complex architectural arrangement of the tarsal bones and weight-bearing nature of the lower extremities. Associated software can provide a variety of options for image reconstruction, including metal artifact reduction, three-dimensional biometric measurements, and digitally reconstructed radiographs. Advancements in this technology have allowed imaging of the knee, hip, hand, and elbow. As more data are published, it is becoming evident that CBCT provides many additional benefits, including fast imaging time, low radiation dose, lower cost, and small equipment footprint. These benefits allow placement of CBCT units outside of the traditional radiology department, including the orthopedic clinic setting. These technologic developments have motivated clinicians to define the scope of CBCT for diagnostics, surgical planning, and longitudinal imaging. As efforts are made to create standardized protocol and measurements, the current understanding and surgical approach for various orthopedic pathologic conditions will continue to shift, with the hope of improving outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Imaging of osteoarthritis from the ankle through the midfoot

Ankle, hindfoot, and midfoot osteoarthritis (OA) is most commonly posttraumatic and tends to become symptomatic in younger patients. It often results from instability due to insufficiency of supportive soft tissue structures, such as ligaments and tendons. Diagnostic imaging can be helpful to detect and characterize the distribution of OA, and to assess the integrity of these supportive structures, which helps determine prognosis and guide treatment. However, the imaging findings associated with OA and instability may be subtle and unrecognized until the process is advanced, which may ultimately limit therapeutic options to salvage procedures. It is important to understand the abilities and limitations of various imaging modalities used to assess ankle, hindfoot, and midfoot OA, and to be familiar with the imaging findings of OA and instability patterns.

MRI in Acute Ankle Sprains: Should We Be More Aggressive with Indications?

Acute ankle sprains are common sports injuries. MRI is the most accurate test for assessing the integrity and severity of ligament injuries in acute ankle sprains. However, MRI may not detect syndesmotic and hindfoot instability, and many ankle sprains are treated conservatively, questioning the value of MRI. In our practice, MRI adds value in confirming the absence or presence of ankle sprain-associated hindfoot and midfoot injuries, especially when clinical examinations are challenging, radiographs are inconclusive, and subtle instability is suspected. This article reviews and illustrates the MRI appearances of the spectrum of ankle sprains and associated hindfoot and midfoot injuries.

Ultrasound-guided joint interventions of the lower extremity

The purpose of this article is to better understand the role ultrasound plays in lower extremity joint interventions. Ultrasound is an important and reliable tool diagnostically and therapeutically. Real-time feedback, lack of ionizing radiation, and dynamic maneuverability make ultrasound an important tool in the proceduralist's armament. This article will touch upon the important anatomic considerations, clinical indications, and technical step-by-step details for lower extremity ultrasound interventions. Specifically, we will look at interventions involving the hip, knee, ankle, and foot. In addition, this article will discuss the roles corticosteroid and platelet-rich plasma may play in certain interventions.

Fractures of the limbs: basic concepts for the emergency department

Traumatic injuries of the limbs are very common and account for a large number of imaging examinations, especially in emergency departments. These injuries can often be resolved if they are recognized and treated appropriately. Their diagnosis requires a complete clinical assessment and the correct interpretation of the appropriate imaging tests. Radiologists play an important role, especially in diagnosing lesions that can go undetected. To this end, radiologists need to know the normal anatomy and its variants, the mechanisms of injury, and the indications for different imaging tests, among which plain-film X-rays are the main technique for the initial evaluation. This article aims to review the relevant characteristics of limb fractures in adults and of lesions that can be associated with these fractures, as well as how to describe them to ensure appropriate clinical management.

Is the diagnostic validity of conventional radiography for Lisfranc injury acceptable?

BACKGROUND

Lisfranc injuries mainly involve the tarsometatarsal joint complex and are commonly misdiagnosed or missed in clinical settings. Most medical institutions prefer to use conventional radiography. However, existing studies on conventional radiographs in Lisfranc injury lack a large population-based sample, influencing the validity of the results. We aimed to determine the diagnostic validity and reliability of conventional radiography for Lisfranc injury and whether computed tomography can alter clinical decision-making.

METHODS

This retrospective study included 307 patients with, and 100 patients without, Lisfranc injury from January 2017 to December 2019. Diagnosis was confirmed using computed tomography. A senior and junior surgeon independently completed two assessments of the same set of anonymised conventional radiographs at least 3 months apart. The surgeons were then asked to suggest one of two treatment options (surgery or conservative treatment) for each case based on the radiographs and subsequently on the CT images.

RESULTS

All inter- and intra-observer reliabilities were moderate to very good (all κ coefficients > 0.4). The mean (range) true positive rate was 81.8% (73.9%-87.0%), true negative rate was 90.0% (85.0%-94.0%), false positive rate was 10.0% (6.0%-15.0%), false negative rate was 18.2% (13.0%-26.1%), positive predictive value was 96.1% (93.8%-97.8%), negative predictive value was 62.4% (51.5%-69.7%), classification accuracy was 83.8% (76.7%-88.2%), and balanced error rate was 14.1% (10.2%-20.5%). Three-column injuries were most likely to be recognized (mean rate, 92.1%), followed by intermediate-lateral-column injuries (mean rate, 81.5%). Medial-column injuries were relatively difficult to identify (mean rate, 60.7%). The diagnostic rate for non-displaced injuries (mean rate, 76.7%) was lower than that for displaced injuries (mean rate, 95.5%). The typical examples are given. A significant difference between the two surgeons was found in the recognition rate of non-displaced injuries (p = 0.005). The mean alteration rate was 21.9%; the senior surgeon tended to a lower rate (15.6%) than the junior one (28.3%) (p < 0.001).

CONCLUSIONS

The sensitivity, specificity, and classification accuracy of conventional radiographs for Lisfranc injury were 81.8%, 90.0%, and 83.8%, respectively. Three-column or displaced injuries were most likely to be recognized. The possibility of changing the initial treatment decision after subsequently evaluating computed tomography images was 21.9%. The diagnostic and clinical decision-making of surgeons with different experience levels demonstrated some degree of variability. Protected weight-bearing and a further CT scan should be considered if a Lisfranc injury is suspected and conventional radiography is negative.

Particularities on Anatomy and Normal Postsurgical Appearances of the Ankle and Foot

The anatomy of the ankle and foot is complex, allowing for a wide range of functionality. The movements of the joints represent a complex dynamic interaction. A solid understanding of the characteristics and actions of the anatomic elements helps explain the mechanisms and patterns of injury. This article reviews the anatomy, with special focus on concepts that are the object of recent study and the features that favor the development of symptoms. Good understanding of the surgical procedures helps in providing information to guarantee a favorable outcome. We review the commonly expected postsurgical appearances and the most common postsurgical complications.

Comparing bilateral feet computed tomography scans can improve surgical decision making for subtle Lisfranc injury

INTRODUCTION

Subtle Lisfranc injuries (SLIs) are challenging to diagnose. Although weightbearing (WB) radiographs have been suggested to identify SLIs, approximately 20% are missed on initial radiographic assessment. Computed tomography (CT) has been suggested as an alternative, but has not provided any diagnostic guideline. Therefore we compared measurement techniques on radiographs and bilateral foot CT scans for the efficiency of diagnosis and making surgical decisions for SLI.

METHODS

We retrospectively investigated patients diagnosed with SLIs between January 2014 and January 2020. Distances between both medial cuneiform and second metatarsal base (C1M2), and the first and second metatarsal bases (M1M2), were measured on bilateral WB radiographs. Bilateral foot CT scans were taken, and the distances between C1M2 were checked on the axial and three points of the coronal plane (top, middle, and base). The surgical indication was > 1 mm of diastasis on CT scan. Clinical outcomes were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score at final follow-up. Intraobserver and interobserver agreements were assessed.

RESULTS

Thirty patients with SLIs were reviewed. Twenty-four patients underwent surgical fixation (Group A) and six patients were treated conservatively (Group B). The side-to-side difference (STSD) of C1M2 and M1M2 distances greater than 1 mm showed 91.7% and 54.2% sensitivity, and 66.7% and 16.7% specificity, respectively. Investigating STSDs of all points on CT scans were informative to discriminate both groups (P ≤ 0.038). Clinical outcomes showed no significant difference between the groups (P = 0.631). Intraclass and interclass correlation coefficient values showed good to very good reliability, except for STSD of WB M1M2 distance and the coronal top plane.

CONCLUSION

Investigating bilateral foot CT scans was significantly efficient and reliable for the diagnosis and treatment plan for SLI. On radiographs, STSD of WB C1M2 distance was more sensitive than STSD of WB M1M2 distance.

LEVEL OF EVIDENCE

Case control study; III.

Computed Tomography Scan Architectural Measurements in Adult Foot and Ankle Surgery: A Narrative Review for Orthopaedic Trainees

CT scan plays an important role in adult foot and ankle surgery. Plain radiographs are usually the first-line imaging modality for assessing foot and ankle bone and joint architectural abnormalities. However, despite the fact that a CT scan is more expensive and associated with higher radiation exposure, it offers better imaging quality for the assessment of bony lesions in orthopaedics and trauma. Evidence has shown that more accurate measurements can be obtained from a CT scan compared to plain radiographs. Weight-bearing multi-detection CT scanning goes the extra mile by providing a more detailed assessment, especially for intra-articular fractures, and mirrors the real-life foot and ankle dynamics compared to conventional non-weight-bearing CT scans. It also has a relatively lower radiation dose compared to conventional CT scans. CT scan is the best modality for assessing bony lesions whereas MRI is better for soft tissue pathology. An understanding of the role of CT scan in the anatomical assessment of the foot and ankle will help improve communication between orthopaedic surgeons, radiologists, and radiographers. A thorough understanding of when to use a CT scan compared to the other imaging modalities will also lead to better surgical outcomes, reduced cost, and reduced risk from radiation exposure. This review article analyzes the role of CT in assessing relevant radiographic architectural measurements for diagnosis and surgical planning in adult foot and ankle surgery.

Support system of Lisfranc joint complex: An anatomical investigation with an evolutionary perspective

BACKGROUND

The anatomical arrangement of the Lisfranc joint between the midfoot and forefoot is complex and not just critical for bipedal gait but also for prevention, management, and rehabilitation of injuries in this region.

MATERIAL AND METHODS

In forty adult cadaveric lower limbs, the Lisfranc mortise, the ligaments and supports were observed and noted.

RESULTS

The structural arrangement that accords stability to the joint has osseous, ligamentous, and tendinous components. A bony mortise, which is deep medially, disrupts the linearity of the joint line. An extensive Lisfranc ligament with confluent interosseous and plantar parts was observed. Tibialis posterior, peroneus Longus and Lisfranc ligament exhibit a unique anatomical arrangement that supports the joint inferiorly.

CONCLUSION

The study documents a unique lattice of tendons and ligament offering dynamic support to the joint. Demands of assumption of erect posture and bipedal walking in humans like adduction of the first ray of the foot, maintenance of longitudinal and transverse arches of the foot and ability stiffen midfoot for efficient forefoot take-off are well reflected in the joint structure and supports.

Deep Learning Algorithms Improve the Detection of Subtle Lisfranc Malalignments on Weightbearing Radiographs

BACKGROUND

Detection of Lisfranc malalignment leading to the instability of the joint, particularly in subtle cases, has been a concern for foot and ankle care providers. X-ray radiographs are the mainstay in the diagnosis of these injuries; thus, improving the performance of clinicians in interpreting radiographs can noticeably affect the quality of health care in these patients. Here we assessed the performance of deep learning algorithms on weightbearing radiographs for detection of Lisfranc joint malalignment in patients with Lisfranc instability.

METHODS

In a retrospective study, 640 patients with Lisfranc malalignment leading to instability were recruited plus 640 individuals with uninjured feet and healthy Lisfranc joint as the control group. All radiographs were screened by orthopaedic surgeons. Two deep learning models were trained, validated, and tested (in a ratio 80:10:10) using a single-view (anteroposterior) and 3-view (anteroposterior, lateral, oblique) radiographs. The performances of the models were reported as sensitivity, specificity, positive and negative predictive values, accuracy, F score, and area under the curve (AUC).

RESULTS

No significant differences were observed between the patients and the controls regarding age, gender, race, and body mass index. The best deep learning algorithm outperformed our human interpreters (<1% vs ~10% misdiagnosis), 94.8% sensitivity, 96.9% specificity, 98.6% accuracy, 95.8% F score, and 99.4% AUC.

CONCLUSION

Deep learning methods have shown promising potential in acting as an assistant interpreter of radiographic images in patients with Lisfranc malalignment. Developing these algorithms can hasten and improve the accuracy of diagnosis and reduce further costs and burdens on the patients and health care system.

LEVEL OF EVIDENCE

Level III, case-control Machine Learning study.

Weight-Bearing Computed Tomography of the Foot and Ankle in the Pediatric Population

BACKGROUND

Newer cone-beam computed tomography (CT) technology has grown in popularity for evaluation of foot and ankle pathology in the weight-bearing (WB) position. Many studies have demonstrated its benefits within the adult population, but there is a paucity of its use within the pediatric literature. The purpose of this study was to describe the indications and clinical findings of WBCT within a pediatric population.

METHODS

A retrospective cohort of 68 patients (86 extremities) who underwent WBCT for a variety of conditions were compared with 48 patients (59 extremities) who underwent traditional supine nonweight-bearing (NWB) CTs. Clinical indications, demographic data, radiation doses, and cost were obtained from the medical record. WBCTs were obtained in a private outpatient orthopaedic clinic, and the conventional NWBCTs were obtained within a hospital-based system.

RESULTS

The most common indications for obtaining a WBCT and NWBCT in our study were fracture, tarsal coalition, and Lisfranc injury. The average WBCT radiation dose was 0.63 mGy for patients <100 lbs and 1.1 mGy for patients >100 lbs undergoing WBCT. For NWBCTs, the average radiation dose was 7.92 mGy for patients <100 lbs and 10.37 mGy for patients greater than 100 lbs. There was a significant reduction in radiation dose for all patients who underwent WBCT (P<0.0001 vs. 0.002). The average reimbursement for NWBCTs was $505 for unilateral studies and $1451 for bilateral studies. The average reimbursement for the WBCTs was $345 for unilateral studies and $635 for bilateral studies.

CONCLUSIONS

WBCT offers a new modality for studying complex foot and ankle pathoanatomy in the pediatric population at a reduced radiation exposure and reduced cost.

LEVEL OF EVIDENCE

Level III-a retrospective comparative study.

Clinical and Radiologic Results of a Human Bone Graft Screw in Tarsometatarsal II/+III Arthrodesis

BACKGROUND

For arthrodesis of the tarsometatarsal joints, there is the possibility of using a transplant screw made of allogenic human bone material (Shark Screw). This article investigates the clinical outcome and radiologic integration of the allogenic bone screw for arthrodesis of the tarsometatarsal joints II/+III.

METHODS

This is a prospective study involving 20 feet of 17 patients who received TMT II/+III arthrodesis with an allogenic bone screw. A visual analog scale (VAS pain and function), Foot Function Index (FFI), American Orthopaedic Foot & Ankle Society (AOFAS) midfoot score, and Foot and Ankle Outcome Score (FAOS) were used as measures to compare preoperative with postoperative results. Radiologic integration in the recipient bone was also evaluated.

RESULTS

A significant mean pre- to postoperative improvement of all evaluated scores has been observed (P < .05) after a mean follow-up of 15.87 months (minimum 12 months, maximum 33 months). VAS score (pain) decreased from 7.6 to 1.4 points as well as a decrease of the VAS (function) from 7.25 to 1.8 points. Further, a reduction of the FFI from 62.3% to 16.7% and an increase from 29.7 to 79.9 points of the AOFAS was detected. Analyzing the FAOS score, in all surveyed subscales, there was an increase in the score (Symptoms: 55.2 to 85.6 points; Pain: 30.5 to 86.9 points; Function: 33.1 to 88.3 points; Quality of life: 27.8 to 79.7 points). Moreover, in all cases, a complete radiologic integration into the receiving bone was appreciated, and after a minimum follow-up time from 12 months, the screw in 19 feet (95%) was no longer distinguishable from the original bone.

CONCLUSION

With these first results of the allogenic bone screw in TMT II/+III arthrodesis, a significant improvement from preoperative to postoperative was confirmed in the collected scores, and a full radiographic integration was demonstrated in all feet.

Novel values in the radiographic diagnosis of ligamentous Lisfranc injuries

BACKGROUND

Ligamentous Lisfranc instability is commonly missed on unilateral radiographs. However, measurement protocols for bilateral weightbearing radiographs have not been standardized. The primary aim of this study was to investigate the optimal cut-off values for diagnosing Lisfranc instability by evaluating the side-to-side differences of preoperative bilateral weightbearing radiographs among patients with surgically-confirmed ligamentous Lisfranc instability. A secondary aim was to investigate whether the midfoot measurements for detecting Lisfranc injury could also be used in patients with a pre-existing bilateral Hallux Valgus (HV) deformity by evaluating whether the Lisfranc measurements could be affected by a foot deformity as HV.

PATIENTS AND METHODS

Patients who underwent surgical repair of ligamentous Lisfranc instability, as well as a separate cohort with bilateral hallux valgus deformity, were included in this multicenter retrospective cohort study. A standardized radiographic measurement protocol was used to assess the midfoot and a receiver operator correlation (ROC) analysis was used to identify the optimal cut-off value for measurements. Interclass Correlation (ICC) scores were calculated to assess the interrater reliability of the Lisfranc area measurement.

RESULTS

Forty-seven patients were included in the Lisfranc group with a mean age of 33 (± 15) years and 25 patients were included in the HV group with a mean age of 51 (± 15) years. For the Lisfranc group, measurements that demonstrated a significant side-to-side difference included; increased C1M2 diastasis of 2.4 mm (± 1.4, P<0.001), increased C1M2 surface area of 24 mm² (± 15, P<0.001), C2M2 malignment by 1.7 mm (± 1.2, P<0.001), second tarsometatarsal joint dorsal step-off sign by 0.8 mm (± 0.7, P<0.001), and arch height by 2.5 mm (± 6.4, P<0.048), all greater on the injured side. In the HV group, side-to-side measurements were not significantly different. There was no significant difference comparing the M1M2 measurement in the HV group with the injured (P = 0.16) or uninjured (P = 0.08) foot in the Lisfranc group. The optimal cut-off points were between the injured and uninjured foot in the Lisfranc group were 2.1 mm for C1M2 diastasis, 0.7 mm for the C2M2 alignment, and 30 mm² for the C1M2 surface area. The ICC-score for the second C1M2 area measurement was 0.88.

CONCLUSION

Bilateral foot weightbearing radiographs can effectively diagnose ligamentous Lisfranc instability using a standardized measurement protocol. Malalignment of the medial aspect of the second metatarsal base ≥0.3 mm relatively to the intermediate cuneiform offers a high sensitivity, and distance ≥2.1 mm between the second metatarsal base and the medial cuneiform has a high specificity. Intermetatarsal distance between the first and second metatarsal base has a low sensitivity and specificity and should not be used in solitary for diagnosis.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Lisfranc injury: Refined diagnostic methodology using weightbearing and non-weightbearing radiographs

BACKGROUND

To compare diagnostic parameters for Lisfranc instability on WB and NWB radiographs and to assess the inter-observer reliability of a standardized diagnostic protocol.

PATIENTS AND METHODS

Patients who had undergone surgical treatment for subtle, purely ligamentous Lisfranc injury with both WB and NWB post-injury, pre-surgery films (n = 26) were included in this multicentre, retrospective comparative study. Also included was a control group (n = 26) of patients with isolated fifth metatarsal avulsion fractures who similarly had both WB and NWB films. Multiple midfoot distance and alignment measurements were used to evaluate the Lisfranc joint on both WB and NWB views. To evaluate interobserver reliability, measurements were made by two independent observers across a cohort subset.

RESULTS

When comparing the NWB views between groups, only C1M2 (medial cuneiform- second metatarsal) distance was found to be significantly larger (∆ = 1.35 mm, p <0.001) for Lisfranc injuries. Most notably, C2M2 (Intermediate cuneiform - second metatarsal) step off-caused by lateral translation of the second metatarsal base-was not significantly different (∆ = 0.39 mm, p = 0.101) between Lisfranc patients and controls. On WB views, Lisfranc patients had significantly larger changes to C1M2 distance and C2M2 step-off as compared to controls (∆ = 2.97 mm, p <0.001 and ∆ =  1.98 mm, p <0.001 respectively). M1M2 (first to second intermetatarsal) distance was not significantly different between patients and controls in WB films. Within the cohort of ligamentous Lisfranc patients, C1M2 distance and C2M2 step-off were significantly larger in WB when compared to NWB films (∆ =  1.77 mm, p <0.001 and ∆ =  1.58 mm, p <0.001 respectively). For these parameters, inter-observer reliability scores (ICC) of >0. 90 were found when interpreting WB radiographs and ICC's ranging between 0.61 and 0.80 were found when interpreting NWB radiographs.

CONCLUSION

Using WB imaging for diagnosing subtle Lisfranc instability reveals larger diastasis in the tarsometatarsal joint and has a higher interobserver reliability compared to NWB imaging. Clinical concern for subtle or occult Lisfranc instability in any patient should therefore trigger WB radiographic assessment since such injuries may be missed on NWB views.

Two Sides of the Same Coin: Tendoligamentous Similarities and Dissimilarities of Great Toe and Thumb Anatomy on MRI

Evolution and functional necessities have compelled the great toe of the foot and its embryological kin, thumb, to have some tendoligamentous differences with a similar basic anatomical structure. This provides biomechanical advantage to these joints: the thumb is apposable and more mobile, ensuring hand dexterity and tool-handling, whereas the great toe is less mobile and more stable, ensuring weight bearing, strength, and stability for bipedal locomotion. This pictorial review will methodically illustrate the similarities and dissimilarities of the joint morphology and its tendoligamentous attachments at the level of carpometacarpal joint, metacarpophalangeal joint, and interphalangeal joints of thumb compared with tarsometatarsal joint, metatarsophalangeal joint, and interphalangeal joints of great toe. It intends to provide a comprehensive understanding of the normal anatomy of great toe and thumb to the radiologists, enabling better interpretation of the pathologies.

Reliability of various diastasis measurement methods on weightbearing radiographs in patients with subtle Lisfranc injuries

OBJECTIVE

This study aimed to evaluate the reliability of the diastasis measurements between the medial cuneiform and the second metatarsal on weightbearing radiography.

MATERIALS AND METHODS

We retrospectively examined 18 patients who underwent open surgery for subtle Lisfranc injuries. Preoperative weightbearing radiography of the affected and unaffected feet was evaluated in all patients. The diastasis between the medial cuneiform and the second metatarsal was measured in both feet using the following four methods: diastasis between parallel lines, distal point diastasis, middle point diastasis, and proximal point diastasis. Intraclass correlation coefficients with consistency of agreement were calculated to evaluate inter- and intraobserver reliability.

RESULTS

The intra- and interobserver reliabilities of all four methods were good. Intraclass correlation coefficients for intraobserver reliability ranged from 0.87 to 0.93. Those for interobserver reliability ranged from 0.81 to 0.91.

CONCLUSIONS

The reliabilities of the diastasis measurement methods between the medial cuneiform and the second metatarsal on weightbearing radiography were good. Measuring the diastasis between the medial cuneiform and the second metatarsal on weightbearing radiography is useful in evaluating subtle injuries when uniform measurement methods are used.

Lisfranc Sprain with Second Metatarsal Base Adaptive Stress Response in High-Level Athletes: Case Series and Novel Perspective on a Distinct Entity of Chronic Low-Energy Lisfranc Injury

Lisfranc injury is increasingly being recognised in the high-performance athletic cohort, particularly in contact sports. In this cohort, there is a pattern of low-energy Lisfranc injury which combines magnetic resonance findings of both ligamentous sprain and adaptive bone stress response that infers a longer timeframe of stress than the duration of symptoms would suggest. This has not been previously described, and the authors believe that this is an unrecognized subset of midfoot sprain in the context of sustained stress to the midfoot. This retrospective case report describes MRI findings of three index cases of this entity in professional athletes presenting with acute foot pain. Two responded with conservative management whilst the third ultimately required surgery. All athletes were eventually able to return to play.

The Diagnostic Accuracy of MRI to Evaluate Acute Lisfranc Joint Injuries: Comparison With Direct Operative Observations

Background:

Early diagnosis is important in patients with Lisfranc joint injury to avoid subsequent complications. As the ligaments in the Lisfranc joint are relatively small and course obliquely, isotropic 3-dimensional (3D) magnetic resonance imaging (MRI) can be beneficial to evaluate ligament injury. The purpose of this study was to investigate the diagnostic accuracy of MRI, including isotropic 3D MRI for acute injury of the Lisfranc joint, especially of the interosseous C1-M2 ligament (Lisfranc ligament), the dorsal C1-M2 ligament (dorsal ligament), and the interosseous C1-C2 ligament, compared with direct operative observations.

Methods:

This retrospective review identified 27 patients who had undergone MR examination for acute Lisfranc joint injury followed by surgery. We reviewed the operative reports that described the Lisfranc, dorsal, and interosseous C1-C2 ligaments. All patients underwent an MRI, including a 2D oblique plane image parallel to the Lisfranc ligament and an isotropic 3D MRI. An image analysis of the integrity of the 3 ligaments and other associated injuries was performed. The diagnostic accuracy of MRI was analyzed using operative findings as a reference standard.

Results:

Lisfranc and dorsal ligament injuries were identified on MRI in all patients. MRI depicted disruption of the interosseous C1-C2 ligament in 12 patients. MRI diagnostic accuracy for detection of Lisfranc, dorsal, and interosseous C1-C2 ligaments was 100% (95% CI 0.82-1.0), 74% (95% CI 0.54-0.89), and 70% (95% CI 0.50-0.86), respectively.

Conclusion:

MRI with oblique planes parallel to the Lisfranc ligament and isotropic 3D MRI was reliable for detecting Lisfranc ligament injury, whereas MRI findings of the dorsal and interosseous C1-C2 ligaments were less consistent with operative observations.

Level of Evidence:

Level IV, case series.

Classification of the interosseous tarsometatarsal ligaments of the foot

BACKGROUND

The aim of this study was to clarify the anatomical features of the interosseous tarsometatarsal ligaments of foot and to classify their types based on the combinations of their ligamentous components.

METHODS

Fifty feet from 27 adult Korean cadavers were dissected.

RESULTS

The interosseous tarsometatarsal ligaments were observed in the first, second, and third cuneometatarsal joint spaces. The interosseous tarsometatarsal ligament of the first cuneometatarsal space consistently connected the medial cuneiform and the second metatarsal, and was accompanied by one or two accessory ligaments above (34%) and/or below (6%) the Lisfranc ligament. The interosseous tarsometatarsal ligaments of the second and third cuneometatarsal joint spaces comprised seven and five components, and were classified into five and three types depending on the number and combination of the components, respectively.

CONCLUSIONS

These results are expected to advance the current knowledge on the tarsometatarsal joint and provide helpful information for more accurate and successful diagnosis and treatment of lesions at this joint.

Computational analysis of the clinical presentation of a ligamentous Lisfranc injury

Lisfranc injuries in the midfoot disrupt key arches of the foot which, if left untreated, can progress to pain, dysfunction, and arthritis. A clinical challenge is that 30-40% of Lisfranc injuries are missed in initial evaluations. The objective of this study was to explore different conditions of limb loading that could influence the biomechanics of the Lisfranc joint in a validated computational model. A computational model was created using SolidWorks software to represent the bones and soft tissues of the lower leg and foot. The model was compared to a cadaveric study of healthy and injured Lisfranc joints. The model was then used to simulate weight-bearing radiographs and evaluate how muscle activity and foot position impacted the diastasis of the Lisfranc joint, a key indicator used to diagnose Lisfranc injuries. The computational model was within one standard deviation of the cadaveric study in all measurements for the healthy and injured foot. When simulating weight-bearing radiographs, the presence of muscle activity or inversion/eversion resulted in less joint separation for the model with ligamentous Lisfranc injuries. While previous research has noted that weight-bearing radiographs provide better conditions to assess Lisfranc injuries than nonweight-bearing, this study suggests that in weight-bearing radiographs both altering the position of the foot, possibly due to pain, and the active contraction of the extrinsic flexor muscles can obfuscate indications of a Lisfranc injury.

The Lisfranc Injury: A Literature Review of Anatomy, Etiology, Evaluation, and Management

Despite being first described in the 1800s, the Lisfranc injury remains one of the most controversial topics in foot and ankle surgery. From the basic anatomy of the ligament complex to the optimal diagnostic and management methods, new research both sharpens and yet confounds our understanding of this unique injury. This article reviews the literature from established and classic papers to recent studies evaluating newer techniques. We discuss the unique bony and ligamentous anatomy, which confer strength to the Lisfranc complex, the typical mechanisms of injury, the most common classification systems, the clinical presentation, current imaging modalities, and conservative and surgical treatment options. We review studies comparing open reduction and internal fixation with primary arthrodesis of acute injuries, in addition to studies evaluating the various methods for obtaining fixation, including intra-articular screws, dorsal plates, and flexible fixation. It is clear from this review that despite the vast number of studies in the literature, much is still to be learned about the diagnosis and management of this challenging injury.Levels of Evidence: Level V: Expert opinion.

Effectiveness and cost-effectiveness of primary arthrodesis versus open reduction and internal fixation in patients with Lisfranc fracture instability (The BFF Study) study protocol for a multicenter randomized controlled trial

Background

The Lisfranc injury is a complex injury of the midfoot. It can result in persistent pain and functional impairment if treated inappropriately. In Lisfranc fracture dislocation, treatment options are primary arthrodesis of the midfoot joints or open reduction and internal fixation. The purpose of the proposed study is to define the optimal treatment for the Lisfranc fracture dislocation, either primary arthrodesis or open reduction and internal fixation, in regard to quality of life, complications, functional outcomes, and cost effectiveness.

Methods

Study design: A prospective multicenter RCT. Study population: All patients of 18 years and older with an acute (< 6 weeks) traumatic fracture dislocation in the Lisfranc midfoot joints, displaced on static radiographic evaluation or unstable with dynamic evaluation, weight bearing radiographs or fluoroscopic stress testing under anesthesia, and eligible for either one of the surgical procedures. In total, this study will include n = 112 patients with Lisfranc fracture dislocation. Interventions: Patients with Lisfranc fracture dislocation will be randomly allocated to treatment in “The Better to Fix or Fuse Study” (The BFF Study) with either PA or ORIF. Main study parameters/endpoints: Primary outcome parameter: the quality of life. Secondary outcomes: complications, functional outcomes, secondary surgical interventions and cost effectiveness. Nature and extent of the burden: PA is expected to have a better outcome, however both treatments are accepted for this injury with a similar low risk of complications. Follow up is standardized and therefore this study will not add extra burden to the patient.

Discussion

This study protocol provides a comprehensive overview of the aims and methods of the attached clinical study. Limitations of this study are the absence of patient blinding since it is impossible in surgical intervention, and the outcome measure (AOFAS) that has limited validity not for these injuries. This study will be the first with enough power to define optimal treatment for Lisfranc fracture dislocations. This is necessary since current literature is unclear on this topic.

Trial registration Current controlled Trial: NCT04519242 with registration date: 08/13/2020. Retrospectively registered; Protocol date and version: Version 4 05/06/2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01320-1.

Isolated Medial Cuneiform Fractures: A Systematic Search and Qualitative Analysis of Case Studies

BACKGROUND

Isolated medial cuneiform fracture is a rare but diagnostically challenging condition. Diagnostic delay in these cases may lead to delays in ideal treatment approaches and prolonged symptoms. An understanding of clinical presentation is needed to expedite diagnosis, facilitate decision making, and guide treatment approach.

METHODS

Case studies/series were searched in four databases until September 2019. Included studies had participants with a history of traumatic closed medial cuneiform fracture. Studies were excluded if the medial cuneiform fractures were open fractures, associated with multitrauma, or associated with dislocation/Lisfranc injury. Three blinded reviewers assessed the methodological quality of the studies, and a qualitative synthesis was performed.

RESULTS

Ten studies comprising 15 patients were identified. Mean ± SD patient age was 38.0 ± 12.8 years, with 86.7% of reported participants being men. The overall methodological quality was moderate to high, and reporting of the patient selection criteria was poor overall. The most commonly reported clinical symptoms were localized tenderness (60.0%) and edema (53.3%). Direct blow was the most common inciting trauma (46.2%), followed by axial load (30.8%) and avulsion injuries (23.1%). Baseline radiographs were occult in 72.7% of patients; magnetic resonance imaging and computed tomography were the most common diagnostic modalities. Mean ± SD diagnostic delay was 64.7 ± 89.6 days. Conservative management was pursued in 54.5% of patients, with reported resolution of symptoms in 3 to 6 months. Surgical intervention occurred in 45.5% of patients and resulted in functional restoration in 3 to 6 months in all but one patient.

CONCLUSIONS

Initial radiographs for isolated medial cuneiform fractures are frequently occult. Due to expedience and relatively low cost, radiographs are still a viable first-line imaging modality. If clinical concern remains, magnetic resonance imaging may be pursued to minimize diagnostic delay. Conservative management is a viable treatment method, with expected return to full function in 3 to 6 months.

Reliability of measurements assessing the Lisfranc joint using weightbearing computed tomography imaging

INTRODUCTION

Subtle Lisfranc joint injuries remain challenging to diagnose in clinical practice. Although of questionable accuracy, bilateral weightbearing radiographs are considered the current gold standard to assess these injuries. However, weightbearing computed tomography (WBCT), which provides clearer visualization of bony landmarks, can also be used for evaluation. This study aims to design a protocol that reliably measures the distance between the medial cuneiform (C1) and second metatarsal (M2) to assess the Lisfranc joint using WBCT imaging.

METHODS

Two unique methods of measuring the C1-M2 distance were designed that localize the center of the interosseous Lisfranc ligament (ILL, reference point). This reference point was located by (I) measuring a specific distance at the M2 base, or (II) approximating from nearby bony landmarks, on both axial (Ax) and coronal (Cor) WBCT images. Four parameters (I-Ax, I-Cor, II-Ax, and II-Cor) were evaluated for each of 96 specimens. Measurements were recorded by three independent observers and repeated for inter- and intra-observer agreement.

RESULTS

In total, 96 patient image series were included and assessed in our study with an average age of 46 (19-66, SD 16.1) and average BMI of 25.8 (17.8-30.5, SD 4.3). I-Ax showed excellent agreement for intra-observer evaluation (R = 0.802) and good agreement for inter-observer evaluation (R = 0.727). I-Cor demonstrated excellent inter- (R = 0.814) and intra-observer (R = 0.840) agreement. Good agreement was found for both II-Ax and II-Cor for both intra- (R = 0.730, R = 0.708) and inter-observer (R = 0.705, R = 0.645) evaluation.

CONCLUSION

Measuring the C1-M2 joint space with coronal WBCT imaging through a protocol that localizes the ILL is reproducible, simple, and can potentially be utilized clinically to evaluate the Lisfranc joint.

Anatomy and biomechanics of the Lisfranc ligamentous complex: A systematic literature review

Lisfranc injuries are challenging to treat and can have a detrimental effect on active individuals. Over the past decade researchers have investigated methods for the reconstruction of the Lisfranc ligamentous complex (LLC) to preserve its functional stability and mobility. To aid in this innovation, this study presents the current understanding of the anatomical and biomechanical characteristics of the LLC through a systematic review. Three medical databases (PubMed, Scopus, and Embase) were searched from inception through July 2019. Original studies investigating the anatomy and/or biomechanical properties of the LLC were considered for inclusion. Data recorded from each study included: number of cadavers, number of feet, gender, laterality, age, type of specimen, measurement methods, reported ligamentous bundles, ligament origins and insertions, geometric characteristics, and biomechanical properties of the LLC. The Quality Appraisal for Cadaveric Studies (QUACS) scale was used to assess the methodologic quality of included articles. Eight cadaveric studies investigating the LLC were included out of 1204 screened articles. Most articles described the LLC as three distinct structures: the dorsal- (DLL), interosseous- (ILL), and plantar- (PLL) Lisfranc Ligaments. The ILL had the largest thickness and insertional area of osseous attachment. Biomechanically, the ILL also had the highest stiffness and resistance to load prior to failure when loaded parallel to its fiber orientation. Current knowledge of the anatomical and biomechanical properties of the LLC are presented and highlight its significant role of stabilizing the tarsometatarsal articulation. Appreciating the biomechanical characteristics of the ILL may improve clinical insight in managing LLC injuries.

Updates on Lisfranc Complex Injuries

Lisfranc injuries are a disruption of one or more of the tarsometatarsal joints and have an estimated incidence of 1/55 000 people. However, the total number of Lisfranc injuries could be underreported, because almost 20% of these injuries are initially missed. Because of the relative infrequency of these injuries, the current literature is inconsistent in regard to proper treatment. This article provides a review of Lisfranc complex injuries including relevant anatomy, diagnosis, treatment, classifications, operative approaches, and outcomes and complications. Based on existing evidence, it also proposes an algorithm the authors prefer for the evaluation and treatment of Lisfranc complex injuries.

Radiographic Value of the Lisfranc Diastasis in a Standardized Population

Introduction. Injury to the Lisfranc's joint, in particular to the second metatarsal-medial cuneiform (second MMC) joint, can be difficult to evaluate, especially in subtle Lisfranc injuries. The purpose of this study was to determine the value of the Lisfranc joint width (diastasis) of the adult foot in a standardized population thereby establishing a potential reference range when investigating this area for potential injury. Methods. The 2nd MMC joint in 50 men and 50 women was evaluated. Individuals with a history of foot/ankle pain, previous foot/ankle operation or fracture, or a history of systemic disease were excluded from the study. Bilateral weightbearing digital anterior-posterior and lateral radiographs were taken using a standardized method. Results. The mean 2nd MMC diastasis in 200 feet was 5.6 mm (95% CI 5.39-5.81). In the female population, the mean 2nd MMC diastasis was 5.8 mm (95% CI 5.51-6.09) as compared with 5.6 mm (95% CI 5.31-5.89) in males. The mean distance between the fifth metatarsal base and first cuneiform in the entire study population was 16.3 mm (95% CI 15.57-17.03). Conclusion. This study helps define baseline measurements of the Lisfranc joint for the general population, which can provide a standard measurement against which suspected foot injuries can be compared.Level of Evidence: Level IV.

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."

Change in the First Cuneiform-Second Metatarsal Distance After Simulated Ligamentous Lisfranc Injury Evaluated by Weightbearing CT Scans

BACKGROUND

This study aimed to investigate the widening between the first cuneiform (C1) and second metatarsal (M2) in a Lisfranc ligamentous complex (LLC) joint injury model subjected to successive ligament dissections evaluated by weightbearing computed tomography (CT) scans.

METHODS

Twenty-four intact cadaveric feet served as the control (condition 1). Each component of the LLC (dorsal, interosseous, and plantar ligaments-conditions 2, 3, and 4, respectively) were then sequentially dissected. The specimens were equally randomized to 1 of 3 additional dissections (first or second tarsometatarsal [TMT] joint capsule or first-second intercuneiform ligament [ICL]-conditions 5a, 5b, and 5c, respectively). One additional ligament was then randomly transected (eg, condition 6ac-transection of the first TMT capsule and ICL). Finally, the remaining ligament was transected (condition 7). After each dissection, CT scans were acquired under nonweightbearing (NWB, 0 kg), partial-weightbearing (PWB, 40 kg), and full-weightbearing (FWB, 80 kg) conditions. The distance between the lateral border of C1 and the medial border of M2 was assessed to evaluate diastasis. Linear regressions with 95% CIs and converted q values were used to compare the measured data.

RESULTS

No significant differences were found within the control. In condition 4, an average axial plane widening relative to control of 1.6 mm (95% CI, 1.5-1.8) and 2.1 mm (95% CI, 1.9-2.2) was observed under PWB and FWB. A coronal plane widening of 1.5 mm (95% CI, 1.3-1.6) and 1.9 mm (95% CI, 1.7-2.1) under PWB and FWB, respectively, was measured. A 95% CI of at least a 2-mm widening during PWB was demonstrated in 5c, 6ac, 6bc, and 7.

CONCLUSIONS

Weightbearing computed tomography (WBCT) scans were used to detect ligamentous Lisfranc injuries in a cadaveric model. Relative axial widening greater than 1.5 mm under PWB conditions could indicate a complete LLC injury. Complete transection of the intercuneiform 1-2 ligament was required to detect a 2-mm widening in the nonweightbearing condition.

CLINICAL RELEVANCE

This study provides insight on the detection of various severities of LLC injuries using WBCT imaging.

Magnetic resonance imaging of the ankle and foot

This article reviews the magnetic resonance imaging (MRI) findings of the normal anatomy and various pathologic conditions of the ankle and foot commonly encountered in clinical practice. The spectrum of entities discussed includes osseous and osteochondral injuries, ligamentous injuries, common traumatic and degenerative tendon pathology, abnormalities of transverse tarsal joint (Chopart) and tarsometatarsal joint (Lisfranc) complexes, pathological conditions affecting capsuloligamentous structures of the great toe and lesser toes, as well as pedal infection, with a focus on diabetic osteomyelitis and neuropathic osteoarthropathy.

Dynamic MR imaging analysis of instability in the injured Lisfranc joint with an MRI-compatible foot stressor device

PURPOSE

To evaluate the applicability of an MRI-compatible foot stressor device in patients with image-proven or clinically suspected Lisfranc joint injuries.

METHOD

This prospective study evaluated Lisfranc joint injury by utilizing a joint-specific, stress device that was engineered to replicate weightbearing and physical examination maneuvers. Sixteen patients with either clinically suspected or image-proven Lisfranc joint injuries were recruited from September 2018 to November 2019 (9 men, 7 women; mean age, 39.3 years; age range, 14-68 years). Resting and stressed MR sequences of the injured and non-injured feet were obtained. Measured values for Lisfranc interval widths, dorsal tarsometatarsal subluxations, and lambda-angles were subtracted between the stressed and resting images to calculate net stress-induced changes. A graded injury schema was used to measure significance.

RESULTS

The foot stressor device reliably generated stress-induced changes in the Lisfranc joint during dynamic MRI examination. All morphologically abnormal ligaments on resting images demonstrated stress-induced changes, whereas all morphologically normal ligaments lacked evidence of instability. More severely injured Lisfranc ligaments allowed greater Lisfranc joint widening (IOL, p < 0.001; PCL, p < 0.001; DCL, p < 0.001). More highly graded DCL injuries allowed greater dorsal TMT subluxation when present (p < 0.001). Angular gain in the midfoot (lambda-angle) correlated with the graded IOL score (p < 0.001). Acute-to-subacute injuries demonstrated greater inducible changes than chronic injuries (p = 0.047). Seven patients underwent surgery and nine patients received physical therapy.

CONCLUSIONS

Stress-induced changes in the midfoot provided information on the degree of ligament pathology and associated joint instability in Lisfranc joint injuries.

Os intermetatarseum: An analysis of morphology and case reports of fracture

INTRODUCTION

The os intermetatarseum is an uncommon accessory ossicle of the foot located dorsally, between the bases of the first and second metatarsals that are usually asymptomatic. In the setting of trauma, this ossicle can clinically mimic a Lisfranc fracture-dislocation, a potentially disabling condition often requiring surgical intervention.

METHODS

In this study, 47 cases of os intermetatarseum were reviewed across several Western Australian (WA) Hospitals and characterised based on morphology. Any fractures were recorded, and their cases were reviewed.

RESULTS

The most common type of os intermetatarseum was freestanding at 63%, followed by the articulating type at 30%. Only 7% were of the fused type. Two acute fractures were identified on plain radiography and computed tomography (CT).

CONCLUSION

The distribution of os intermetatarseum subtypes in the WA population is consistent with previous radiological studies. The two cases of isolated acute os intermetatarseum fracture are described, the first to our knowledge, highlighting the need for increased awareness of this ossicle in the setting of foot trauma.

CT-guided bone marrow aspirations and biopsies: retrospective study and comparison with blind procedures

PURPOSE

To compare the pathology results of CT-guided and blind bone marrow aspirations and biopsies.

METHODS

Ninety-eight consecutive CT-guided biopsies and 98 age- and gender-matched blind (non-CT-guided) posterior iliac crest bone marrow aspirations and biopsies performed in 2017 were reviewed for adequacy of core biopsies and aspirate smears. CT procedure images and CT abdomen/pelvis images were reviewed to evaluate anatomic features of the posterior ilium and soft tissues. Statistical analysis was performed using a T test, Fisher exact test, and Kruskal-Wallis test.

RESULTS

There was no significant difference in the age and gender of the two groups (p > 0.05). However, the CT-guided group had a higher BMI (p = 0.0049) and posterior soft tissue thickness (p = 0.0016). More CT-guided biopsy samples (CT 93 (95%); blind 77 (79%); p = 0.0006) and aspirate smears (CT 90 (92%); blind 78 (80%); p = 0.042) were categorized as adequate. The CT-guided group had longer core lengths (CT 1.4 ± 0.6 (range 0.3-3.5) cm; blind 1.0 ± 0.60 (range 0-2.6) cm; p = 0.0001). Overall, 131/164 (80%) of the cases had at least one of the described features (slanted posterior ilium (angle > 30°), 30%; rounded posterior ilium, 20%; thick posterior ilium cortex, 13%; focal lesion in posterior ilium, 12%; prior procedure in posterior ilium, 5%; posterior soft tissue thickness > 3 cm, 40%).

CONCLUSION

CT-guided bone marrow procedures were more likely to result in both adequate aspirate smears and biopsy samples and longer core lengths when compared with blind procedures.

Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings

Adult acquired flatfoot deformity (AAFD) is a common disorder that typically affects middle-aged and elderly women, resulting in foot pain, malalignment, and loss of function. The disorder is initiated most commonly by degeneration of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially flexible but becomes rigid and constant as the disorder progresses. Tendon dysfunction commonly leads to secondary damage of the spring ligament and talocalcaneal ligaments and may be associated with injury to the deltoid ligament, plantar fascia, and other soft-tissue structures. Failure of multiple stabilizers appears to be necessary for development of the characteristic planovalgus deformity of AAFD, with a depressed plantar-flexed talus bone, hindfoot and/or midfoot valgus, and an everted flattened forefoot. AAFD also leads to gait dysfunction as the foot is unable to change shape and function adequately to accommodate the various phases of gait, which require multiple rapid transitions in foot position and tone for effective ambulation. The four-tier staging system for AAFD emphasizes physical examination findings and metrics of foot malalignment. Mild disease is managed conservatively, but surgical procedures directed at the soft tissues and/or bones become necessary and progressively more invasive as the disease progresses. Although much has been written about the imaging findings of AAFD, this article emphasizes the anatomy and function of the foot's stabilizing structures to help the radiologist better understand this disabling disorder. Online supplemental material is available for this article. ^©RSNA, 2019.

ACR Appropriateness Criteria® Acute Trauma to the Foot

Acute injuries to the foot are frequently encountered in the emergency room and in general practice settings. This publication defines best practices for imaging evaluations for several variants of patients presenting with acute foot trauma. The variants include scenarios when the Ottawa rules can be evaluated, when there are exclusionary criteria, and when suspected pathology is in anatomic areas not addressed by the Ottawa rules. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Imaging in Lisfranc injury: a systematic literature review

OBJECTIVES

To systematically review current diagnostic imaging options for assessment of the Lisfranc joint.

MATERIALS AND METHODS

PubMed and ScienceDirect were systematically searched. Thirty articles were subdivided by imaging modality: conventional radiography (17 articles), ultrasonography (six articles), computed tomography (CT) (four articles), and magnetic resonance imaging (MRI) (11 articles). Some articles discussed multiple modalities. The following data were extracted: imaging modality, measurement methods, participant number, sensitivity, specificity, and measurement technique accuracy. Methodological quality was assessed by the QUADAS-2 tool.

RESULTS

Conventional radiography commonly assesses Lisfranc injuries by evaluating the distance between either the first and second metatarsal base (M1-M2) or the medial cuneiform and second metatarsal base (C1-M2) and the congruence between each metatarsal base and its connecting tarsal bone. For ultrasonography, C1-M2 distance and dorsal Lisfranc ligament (DLL) length and thickness are evaluated. CT clarifies tarsometatarsal (TMT) joint alignment and occult fractures obscured on radiographs. Most MRI studies assessed Lisfranc ligament integrity. Overall, included studies show low bias for all domains except patient selection and are applicable to daily practice.

CONCLUSIONS

While conventional radiography can demonstrate frank diastasis at the TMT joints; applying weightbearing can improve the viewer's capacity to detect subtle Lisfranc injury by radiography. Although ultrasonography can evaluate the DLL, its accuracy for diagnosing Lisfranc instability remains unproven. CT is more beneficial than radiography for detecting non-displaced fractures and minimal osseous subluxation. MRI is clearly the best for detecting ligament abnormalities; however, its utility for detecting subtle Lisfranc instability needs further investigation. Overall, the available studies' methodological quality was satisfactory.

Primary arthrodesis versus open reduction internal fixation for complete Lisfranc fracture dislocations: a retrospective study comparing functional and radiological outcomes

BACKGROUND

The aims of this retrospective study were to compare the functional and radiological outcomes of primary arthrodesis and open reduction internal fixation (ORIF) for the treatment of complete Lisfranc fracture dislocations.

METHODS

A retrospective cohort study of 39 patients treated for a complete Lisfranc fracture dislocation, defined as Myerson types A and C2, over a period of 8 years at a level 1 trauma centre was performed. Of these, 18 underwent primary arthrodesis, and 21 ORIF. The primary outcome measures included the American Orthopaedic Foot and Ankle Society score, the validated Manchester Oxford Foot Questionnaire functional tool, and the secondary outcome was the radiological Wilppula classification of anatomical reduction.

RESULTS

Significantly better functional outcomes were seen in the primary arthrodesis group. These patients had a mean Manchester Oxford Foot Questionnaire score of 30.1 points, compared with 45.1 for the ORIF group (P = 0.017). Similarly, the mean American Orthopaedic Foot and Ankle Society score was 71.8 points in the fusion group versus 62.5 in the ORIF group (P = 0.14). Functional outcome was dependent on the quality of final reduction (P < 0.001). Primary arthrodesis achieved good initial reduction in 83% cases compared to 62% with ORIF (P = 0.138). There was a loss of reduction quality of 47% in the ORIF group over time.

CONCLUSION

Primary arthrodesis for complete Lisfranc fracture dislocations resulted in improved functional outcomes and quality of reduction compared to open reduction and internal fixation.

Pearls and pitfalls of fluoroscopic-guided foot and ankle injections: what the radiologist needs to know

OBJECTIVE

This article provides a comprehensive, joint-by-joint review of fluoroscopic-guided foot and ankle injections and emphasizes pre-procedural planning, relevant anatomy, appropriate technique, troubleshooting the difficult procedure, and the importance of communicating unexpected findings with the referring clinician. The interrogation of pain generators including variant ossicles, fractures, and post-surgical/traumatic findings is also described.

CONCLUSIONS

Even the most challenging foot and ankle injections may be successfully completed with a solid anatomical understanding and thoughtful approach.

Dynamic Stress MRI of Midfoot Injuries: Measurable Morphology and Laxity of the Sprained Lisfranc Ligament During Mechanical Loading: A Case Report

CASE

Our 26-year-old patient is a professional ballet dancer who suffered a classic Lisfranc joint injury while performing a dancing maneuver with his foot in full plantar flexion. Initial workup with radiographs revealed borderline Lisfranc interval widening without definitive joint instability. Further evaluation with an innovative dynamic stress magnetic resonance imaging (MRI) revealed mild interosseous Lisfranc ligament laxity and sprain, which allowed the orthopaedic surgeon to pursue conservative management, rather than surgery. After physical therapy, our patient reports a successful return to dancing.

CONCLUSIONS

Dynamic stress MRI may become a useful technique in evaluating equivocal cases of midfoot injury through the use of new imaging-based criteria.

Pattern Recognition: A Mechanism-based Approach to Injury Detection after Motor Vehicle Collisions

Motor vehicle collisions cause substantial mortality, morbidity, and expense worldwide. Certain types of injuries are more likely to result from frontal versus side-impact collisions, and knowledge of these specific patterns and why they occur aids in accurate and efficient diagnosis of traumatic injuries. Although the proper use of seat belts decreases crash-related mortality during frontal impact, certain injury patterns to the torso are directly attributed to restraint use. The spectrum of seat belt-related injuries ranges from mild skin and soft-tissue contusions to traumatic bowel injuries and unstable spine injuries that require surgery. Impact with the steering wheel or windshield during a frontal crash can cause characteristic injuries to the head, neck, torso, and distal upper extremity. Steering wheel deformity is an independent predictor of serious thoracic and abdominal injury among front-seat passengers. Impact of a flexed knee with the dashboard during a frontal collision can cause knee, thigh, and hip injuries. Distal lower extremity injuries are encountered frequently when the floorboard is driven into the foot. Lateral impact crashes often result in traumatic brain, thoracic, abdominal, and pelvic injuries, which are more often fatal to occupants on the side of the impact. The specific mechanism-based injury patterns are reviewed to establish a structured systematic search pattern that enables the radiologist to identify traumatic injuries with greater accuracy and speed, thereby improving the care of patients who experience acute trauma. ^©RSNA, 2019 See discussion on this article by Ballard and Mellnick .

Naviculocuneiform and Second and Third Tarsometatarsal Articulations: Underappreciated Normal Anatomy and How It May Affect Fluoroscopy-Guided Injections

OBJECTIVE

Because the second and third tarsometatarsal (TMT) and naviculocuneiform joints normally communicate, the least arthritic or technically most straightforward joint was injected when a fluoroscopically guided therapeutic injection was ordered for one or both joints. We hypothesized that pain relief would be equivalent regardless of the joint injected and would result in less radiation and a lower steroid dose compared with patients who had both articulations injected.

MATERIALS AND METHODS

Seventy-eight patients were divided into four joint groups: naviculocuneiform requested and injected (n = 15), nonrequested naviculocuneiform or second and third TMT injected (n = 25), both injected (n = 23), and TMT requested and injected (n = 15). Variables recorded included patient age and sex, fluoroscopy time, steroid dose, pre- and postprocedural pain, osteoarthrosis (OA) grade, and confidence of intraarticular injection. Statistical analysis compared mean pain level change before and after injection, mean fluoroscopy time, and mean steroid dose between groups. The mean OA grade of the nonrequested joint was compared with that of the requested joint in patients whose injected and requested joints did not match (group 2).

RESULTS

Pre- and postinjection pain reduction (p = 0.630) and postinjection pain (p = 0.935) were not significantly different. Mean steroid dose (p < 0.001) and fluoroscopy time (p = 0.0001) were significantly increased for the both joint injection group. Within the nonrequested naviculocuneiform or second and third TMT injection group, there was a significant difference in OA grade between injected (least arthritic) and requested joints (p = 0.001).

CONCLUSION

When faced with challenging naviculocuneiform or second and third TMT joint injections, choosing the technically most straightforward joint may result in less radiation and steroid dose without compromising quality of care or pain reduction.

Radiographic Anatomy of the Pediatric Lisfranc Joint

BACKGROUND

Injuries to the Lisfranc joint in children and adolescents are rare. The incomplete ossification of the bones of the foot makes it difficult to detect injuries.The aim of this study was to determine age-specific radiographic measurements of the Lisfranc joint to provide guidance to the radiologist, emergency physicians, and surgeons to decrease misdiagnosis of Lisfranc injuries and improve detection.

METHODS

We retrospectively reviewed all foot radiographs without traumatic injury made between August 2014 and February 2015 in all patients younger than 18. The attendance list of the Emergency Department and Outpatient Clinic of a level-1 trauma center were used. Using a non-weight-bearing anteroposterior-view of the foot the distance between the base of metatarsal 1 and metatarsal 2 (MT1-MT2) and the distance between the medial cuneiform (MC) and the base of metatarsal 2 (MC-MT2) were measured. Median normal values were calculated per age.

RESULTS

A total of 352 patients between the age of 0 and 18 years were screened for eligibility. Excluded were 109 patients because of anatomic abnormality, a fracture, inadequate radiograph, pain at the base of the first metatarsal, second metatarsal or MC, persisting pain at the Outpatient Clinic checkup or no follow-up. Included in the analysis were 243 patients.

CONCLUSIONS

The distance between the base of MT1-MT2 was constant below 3 mm. Measurements for both MT1-MT2 and MC-MT2 distance approached adult values at the age of 6.

LEVEL OF EVIDENCE

Level III.

Nonoperative, open reduction and internal fixation or primary arthrodesis in the treatment of Lisfranc injuries: a prospective, randomized, multicenter trial - study protocol

Background

Lisfranc injuries are known to be rare and often overlooked injuries that can cause long-term disability and pain when missed or treated incorrectly. The wide variety of Lisfranc injuries ranges from subtle ligament distensions to open fracture dislocations. The treatment of Lisfranc joint injuries is still controversial and very little is known about what types of injury can be treated nonoperatively. The current literature provides only two randomized studies on dislocated Lisfranc injuries. These studies have shown that primary arthrodesis (PA) leads to a similar or better outcome and results in fewer secondary operations when compared with open reduction and internal fixation (ORIF) in ligamentous injuries. There have been no previous randomized studies of the nonoperative versus operative treatment of Lisfranc injuries. Therefore, the purpose of this study is to compare the operative and nonoperative treatment of non-dislocated Lisfranc injuries and to compare the ORIF and PA treatment of dislocated Lisfranc injuries.

Methods

This study is a prospective, randomized, national multi-center trial. The trial comprises two strata: Stratum I compares cast-immobilization versus open reduction and internal fixation (ORIF) treatment of non-dislocated Lisfranc joint injuries. Stratum II compares PA versus ORIF in the treatment of dislocated injuries of the Lisfranc joint. The main hypothesis of stratum I is that the nonoperative treatment of non-dislocated Lisfranc injuries achieves a similar outcome compared with operative treatment (ORIF). The hypothesis of stratum II is that PA of dislocated Lisfranc injuries yields a similar functional outcome compared with ORIF, but that PA results in fewer secondary operations than ORIF. The main outcome measure is the American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot score and the secondary outcome measures are Visual-Analogue-Scale Foot and Ankle (VAS-FA), Visual-Analogue-Scale (VAS), rate of secondary operations and other treatment-related complications. The results will be analyzed after the 2-year follow-up period.

Discussion

This publication presents a prospective, randomized, national multi-center trial study protocol. It provides details of patient flow, randomization, aftercare and methods of analysis of the material and ways to present and publish the results.

Trial registration

ClinicalTrials.gov identifier: NCT02953067 24.10.2016.