Morphology of the Lisfranc Joint Complex.

Lisfranc injuries are complicated injuries of the tarsometatarsal joint with high rates of sequelae. Both anatomy and injury of the Lisfranc joint are variably documented. Descriptions of these injuries and their associated structures vary greatly. The most injured structures are those of the Lisfranc joint complex, which involves the medial cuneiform, second and third metatarsals, and the dorsal, interosseous, and plantar Lisfranc ligaments. This study sought to examine morphology of the Lisfranc joint in cadavers. Twenty-two embalmed cadaveric feet were dissected (13 male, 9 female, 80.3 years ± 14.03) to isolate the bones and ligaments of the Lisfranc joint complex. The dorsal, interosseous, and plantar Lisfranc ligaments were present in each specimen. Each ligament was measured and morphology noted. The dissected dorsal Lisfranc ligament had consistent morphology (mean = 10.8 mm ± 1.79). The interosseous Lisfranc ligament had a consistent path, but 11/17 of specimens possessed a connection to the plantar Lisfranc ligament. The plantar Lisfranc ligament demonstrated wide variability with a Y-variant (n = 3) and a fan-shaped variant (n = 14). Ligament thickness was greatest in the interosseous Lisfranc ligament (mean = 13.74 ± 3.08) and least in the dorsal Lisfranc ligament (mean = 1.36 ± 0.42). While the objective of defining joint and ligament morphology was achieved, further questions were raised. Variations of the interosseous and plantar Lisfranc ligament may play a role in susceptibility to joint injury, and arthritic changes to the joints examined raise questions regarding the prevalence of arthritis in the uninjured Lisfranc joint.

Ultrasound as a Diagnostic Tool in the Assessment of Lisfranc Joint Injuries.

OBJECTIVES: Ligamentous Lisfranc injuries are frequently overlooked because of subtle clinical presentations and diagnostic difficulties. The dorsal Lisfranc ligament (DLL) is easily visualized with ultrasound (US), which can provide quick, cost-effective diagnoses of disorders but is not considered standard clinical practice. This study sought to compare DLL measurement accuracy between US and cadaveric dissection. METHODS: Ultrasound images of 22 embalmed cadaveric feet were obtained with an M-Turbo US machine and a 6-13-MHz linear array (FUJIFILM SonoSite, Inc, Bothell, WA). Images were measured in the US unit and again with ImageJ software (National Institutes of Health, Bethesda, MD). Specimens were dissected, and DLL morphologic characteristics were recorded. RESULTS: Twenty-two specimens were scanned, however 4 were excluded, leaving a sample of 11 male and 7 female cadaveric specimens (mean age ± SD, 80.3 ± 14.03 years). The DLL length differences between SonoSite (8.39 ± 1.27 mm) and ImageJ (8.25 ± 1.84 mm) were not significant (P > .05). Both US DLL measurements significantly differed from the gross dissection measurement (10.8 ± 1.85 mm; P < .001). The morphologic characteristics of the DLL at dissection were consistent. Overall, 70% to 80% of the ligament length was represented by US compared to dissection. The dorsal joint space did not differ significantly between SonoSite (2.19 ± 0.49 mm) and ImageJ (2.05 ± 0.52; P > .05). Both US measurements were also significantly larger than dissection measurements (1.04 ± 0.24; P < .001). Intraclass correlation coefficients indicated good reliability for the DLL length (0.835) and moderate reliability for the dorsal joint space (0.714). CONCLUSIONS: The DLL is underrepresented but easily distinguished by US, demonstrating its utility in Lisfranc injury diagnosis. Thus, we propose a 4-component assessment involving US, which may provide more rapid, cost-effective diagnoses of subtle Lisfranc injuries.

Morphological variations and accessory ossicles in the peroneal and tibialis muscles.

This study describes five bilateral anatomical variations in the feet of a 97-year-old male cadaver. Following routine dissection, all variants were measured and documented. Three accessory tendons and two accessory ossicles were identified. Bilateral accessory tendons were present from the tibialis anterior (type II), peroneus tertius (type III), and peroneus brevis muscles. Accessory tendon length was 36-104 mm and width was 1-3 mm each inserting more distally then the main tendon. Accessory ossicles were identified as an accessory navicular and os peroneum, respectively. Individually, each variation has varying prevalence rates in the literature, but to date, no known studies have been published describing the combined presence of all five bilateral variations. The acknowledgement of multi-variant cases such as this one may be helpful in the clinical setting, particularly for patients with pathology or for those undergoing foot and ankle surgery.