Evaluation of dorsal Lisfranc ligament deformation with load using ultrasound imaging

Retrospective chart review: Weightbearing CT scans and the measurement of the Lisfranc ligamentous complex

BACKGROUND

Lisfranc Ligamentous Complex (LLC) injuries are commonly misdiagnosed due to their unreliable projection on plain films. Weightbearing CT (WBCT) scans are a relatively new imaging modality that has not yet been utilized to establish widely referenced baseline anatomic positions.

METHODS

A retrospective chart review was conducted of patients who had undergone weightbearing CT of the bilateral lower extremities with one-hundred and twelve being included (56 patients). Measurements of the Lisfranc joint were collected by two independent reviewers. Uninjured symmetric anatomy was used to describe a baseline for normal anatomic variation and to evaluate for sex-based or age-related differences. These measurements were then compared against the injured side.

RESULTS

In patients without Lisfranc injury, the 1st metatarsal base to 2nd metatarsal base distance (Base M1-M2) was 2.7 + /- 0.7 mm; 2nd metatarsal base to medial cuneiform (M2-C1) was 3.7 + /- 0.7 mm; intercuneiform distance was 1.2 + /- 0.3 mm; and sagittal descent 12.2 + /- 5.4 mm. Patients with injury to LLC had a larger M1-M2 base distance (Δ = 0.5903, p < 0.0001) and M2-C1 interval (Δ = 1.8008, p < 0.0001) compared to uninjured side. Males had significantly higher M2-C1 (p = 0.0031), intercuneiform distance (p = 0.0039), and sagittal descent (p = 0.0008) compared to female patients. No significant differences were found between left versus right side in any of the measurements. Intercuneiform distance (p = 0.0039) was found to significantly decrease as age increased, while sagittal descent significantly increased with increased age (p = 0.0066).

CONCLUSION

Weightbearing CT has high utility in identification of Lisfranc injuries particularly when comparing injured and uninjured sides, which may be its greatest utility in defining injuries. This is evident in the excellent diagnostic ability of the M2-C1 measurement. By defining baseline anatomic measurements for Lisfranc complex parameters in our patient population, we provide normal parameters for comparison when evaluating potential subtle injuries.

LEVEL OF EVIDENCE

III.

Using area and volume measurement via weightbearing CT to detect Lisfranc instability

Weightbearing CT (WBCT) allows evaluation of the Lisfranc joint under physiologic load. We compared the diagnostic sensitivities of one-dimensional (1D) distance, two-dimensional (2D) area, and three-dimensional (3D) volumetric measurement of the injured Lisfranc joint complex (tarsometatarsal, intertarsal, and intermetatarsal) on WBCT among patients with surgically-confirmed Lisfranc instability. The experimental group comprised of 14 patients having unilateral Lisfranc instability requiring operative fixation who underwent preoperative bilateral foot and ankle WBCT. The control group included 36 patients without foot injury who underwent similar imaging. Measurements performed on WBCT images included: (1) Lisfranc joint (medial cuneiform-base of second metatarsal) area, (2) C1-C2 intercuneiform area, (3) C1-M2 distance, (4) C1-C2 distance, (5) M1-M2 distance, (6) first tarsometatarsal (TMT1) angular alignment, (7) second tarsometatarsal (TMT2) angular alignment, (8) TMT1 dorsal step off distance, and (9) TMT2 dorsal step-off distance. In addition, the volume of the Lisfranc joint in the coronal and axial plane were calculated. Among patients with unilateral Lisfranc instability, all WBCT measurements were increased on the injured side as compared to the contralateral uninjured side (p values:  <.001-.008). Volumetric measurements in the coronal and axial plane had a higher sensitivity (92.3%; 91.6%, respectively) and specificity (97.7%; 96.5%, respectively) than 2D and 1D Lisfranc joint measurements, suggesting them to be the most accurate in diagnosing Lisfranc instability. The control group showed no difference in any of the measurements between the two sides. WBCT scan can effectively differentiate between stable and unstable Lisfranc injuries. Lisfranc joint volume measurements demonstrate high sensitivity and specificity, suggesting that this new assessment has high clinical implications for diagnosing subtle Lisfranc instability.

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.

Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review

The critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

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.