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Function of anterior talofibular and calcaneofibular ligaments during in-vivo motion of the ankle joint complex.

de Asla RJ, Kozánek M, Wan L, Rubash HE, Li G - J Orthop Surg Res (2009)

Bottom Line: The ATFL elongated significantly from 14.8 +/- 2.5 mm at maximal pronation to 17.4 +/- 3.0 mm at maximal supination (p = 0.08).The results showed that the ATFL elongates more during plantarflexion and supination whereas the CFL increases in length with dorsiflexion and pronation.Furthermore, in the case of surgical reconstruction the grafts used to reconstruct the two ligaments may need to be tensioned at different positions of the ankle in order to reproduce their natural in vivo function.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street - GRJ 1215, Boston, MA 02114, USA. gli1@partners.org.

ABSTRACT

Background: Despite the numerous in-vitro studies on the mechanical properties and simulated injury mechanisms of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), the in-vivo biomechanical behavior of these two ligaments has not yet been described.

Methods: Apparent length of the ATFL and CFL was measured in four ankles in healthy male subjects between 32 and 45 years of age (two left and two right) during a dorsiflexion-plantarflexion and supination-pronation arc of motion using a combined dual-orthogonal fluoroscopic and magnetic resonance imaging technique.

Results: The ATFL elongated from the neutral position at 16.3 +/- 3.0 mm to 20.8 +/- 2.7 mm at maximal plantarflexion and shortened significantly from the neutral position to 13.9 +/- 2.9 mm at maximal dorsiflexion (p = 0.01). The CFL shortened from the neutral position at 28.0 +/- 2.9 mm to 26.6 +/- 2.2 mm at maximal plantarflexion (p = 0.08) and elongated significantly from the neutral position to 29.9 +/- 3.0 mm at maximal dorsiflexion (p = 0.003). The ATFL elongated significantly from 14.8 +/- 2.5 mm at maximal pronation to 17.4 +/- 3.0 mm at maximal supination (p = 0.08). At the same time, the CFL shortened from 31.0 +/- 3.8 mm at maximal pronation to 26.9 +/- 3.6 mm at maximal supination (p = 0.02).

Conclusion: The results showed that the ATFL elongates more during plantarflexion and supination whereas the CFL increases in length with dorsiflexion and pronation. Concurrently, these data also demonstrated the reciprocal function between the two ligaments. While one shortens, the other one elongates. The different elongation of the ATFL and CFL during the same motion arc suggests that under excessive loading conditions the ATFL might be more vulnerable in plantarflexion and supination while the CFL might be more susceptible to injury in dorsiflexion and pronation. Furthermore, in the case of surgical reconstruction the grafts used to reconstruct the two ligaments may need to be tensioned at different positions of the ankle in order to reproduce their natural in vivo function.

No MeSH data available.


Related in: MedlinePlus

(a) MR image of the ankle joint complex (AJC) used to create a three-dimensional virtual model (b) 3D model of the AJC with anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).
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Figure 1: (a) MR image of the ankle joint complex (AJC) used to create a three-dimensional virtual model (b) 3D model of the AJC with anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).

Mentions: Each ankle was MR imaged on a 1.5 T scanner (GE, Milwaukee, WI) using a surface coil and three-dimensional spoiled gradient-recalled echo (3D SPGR) sequence with the subject lying in a relaxed, supine position. During the MR scanning the ankle was held in a brace with the foot at a right angle with respect to the shaft of the tibia. This position was considered a neutral reference position. A field of view (16 × 16 × 10 cm3) that spanned the medial and lateral boundaries of the ankle joint complex (AJC) (which we define as the distal tibia, fibula, talus, calcaneus, the tibiotalar joint, and subtalar joint) was created from the MR scan with 16 cm in both anterior-posterior and proximal-distal directions and 10 cm in the medial-lateral direction. Parallel, sagittal, coronal and axial images with a resolution of 512 × 512 pixels were taken, separated at 1 mm intervals (a sample sagittal MR slice is shown on Figure 1a). The sagittal MR images were imported into solid modeling software (Rhinoceros®, Robert McNeel and Associates, Seattle, WA) and digitized to outline the contours of tibia, fibula, talus, and calcaneus. Afterwards, these outlines were used to reconstruct 3D geometric models of the AJC (Figure 1b) [11-13]. The ligament attachment sites were determined from the MR images with the assistance of anatomical studies.[5,14] Once the MR images of each studied AJC were obtained, they were imported into virtual environment of the solid modeling software where the insertions were digitally outlined on each MR slice. Thereafter, an orthopedic surgeon specializing in foot and ankle surgery as well as a musculoskeletal radiologist verified the outlined insertions on each studied AJC. Furthermore, in preparation for this study we also dissected four cadaveric ankle specimens and meticulously identified the insertion site anatomy of ATFL and CFL.


Function of anterior talofibular and calcaneofibular ligaments during in-vivo motion of the ankle joint complex.

de Asla RJ, Kozánek M, Wan L, Rubash HE, Li G - J Orthop Surg Res (2009)

(a) MR image of the ankle joint complex (AJC) used to create a three-dimensional virtual model (b) 3D model of the AJC with anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2666648&req=5

Figure 1: (a) MR image of the ankle joint complex (AJC) used to create a three-dimensional virtual model (b) 3D model of the AJC with anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).
Mentions: Each ankle was MR imaged on a 1.5 T scanner (GE, Milwaukee, WI) using a surface coil and three-dimensional spoiled gradient-recalled echo (3D SPGR) sequence with the subject lying in a relaxed, supine position. During the MR scanning the ankle was held in a brace with the foot at a right angle with respect to the shaft of the tibia. This position was considered a neutral reference position. A field of view (16 × 16 × 10 cm3) that spanned the medial and lateral boundaries of the ankle joint complex (AJC) (which we define as the distal tibia, fibula, talus, calcaneus, the tibiotalar joint, and subtalar joint) was created from the MR scan with 16 cm in both anterior-posterior and proximal-distal directions and 10 cm in the medial-lateral direction. Parallel, sagittal, coronal and axial images with a resolution of 512 × 512 pixels were taken, separated at 1 mm intervals (a sample sagittal MR slice is shown on Figure 1a). The sagittal MR images were imported into solid modeling software (Rhinoceros®, Robert McNeel and Associates, Seattle, WA) and digitized to outline the contours of tibia, fibula, talus, and calcaneus. Afterwards, these outlines were used to reconstruct 3D geometric models of the AJC (Figure 1b) [11-13]. The ligament attachment sites were determined from the MR images with the assistance of anatomical studies.[5,14] Once the MR images of each studied AJC were obtained, they were imported into virtual environment of the solid modeling software where the insertions were digitally outlined on each MR slice. Thereafter, an orthopedic surgeon specializing in foot and ankle surgery as well as a musculoskeletal radiologist verified the outlined insertions on each studied AJC. Furthermore, in preparation for this study we also dissected four cadaveric ankle specimens and meticulously identified the insertion site anatomy of ATFL and CFL.

Bottom Line: The ATFL elongated significantly from 14.8 +/- 2.5 mm at maximal pronation to 17.4 +/- 3.0 mm at maximal supination (p = 0.08).The results showed that the ATFL elongates more during plantarflexion and supination whereas the CFL increases in length with dorsiflexion and pronation.Furthermore, in the case of surgical reconstruction the grafts used to reconstruct the two ligaments may need to be tensioned at different positions of the ankle in order to reproduce their natural in vivo function.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street - GRJ 1215, Boston, MA 02114, USA. gli1@partners.org.

ABSTRACT

Background: Despite the numerous in-vitro studies on the mechanical properties and simulated injury mechanisms of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), the in-vivo biomechanical behavior of these two ligaments has not yet been described.

Methods: Apparent length of the ATFL and CFL was measured in four ankles in healthy male subjects between 32 and 45 years of age (two left and two right) during a dorsiflexion-plantarflexion and supination-pronation arc of motion using a combined dual-orthogonal fluoroscopic and magnetic resonance imaging technique.

Results: The ATFL elongated from the neutral position at 16.3 +/- 3.0 mm to 20.8 +/- 2.7 mm at maximal plantarflexion and shortened significantly from the neutral position to 13.9 +/- 2.9 mm at maximal dorsiflexion (p = 0.01). The CFL shortened from the neutral position at 28.0 +/- 2.9 mm to 26.6 +/- 2.2 mm at maximal plantarflexion (p = 0.08) and elongated significantly from the neutral position to 29.9 +/- 3.0 mm at maximal dorsiflexion (p = 0.003). The ATFL elongated significantly from 14.8 +/- 2.5 mm at maximal pronation to 17.4 +/- 3.0 mm at maximal supination (p = 0.08). At the same time, the CFL shortened from 31.0 +/- 3.8 mm at maximal pronation to 26.9 +/- 3.6 mm at maximal supination (p = 0.02).

Conclusion: The results showed that the ATFL elongates more during plantarflexion and supination whereas the CFL increases in length with dorsiflexion and pronation. Concurrently, these data also demonstrated the reciprocal function between the two ligaments. While one shortens, the other one elongates. The different elongation of the ATFL and CFL during the same motion arc suggests that under excessive loading conditions the ATFL might be more vulnerable in plantarflexion and supination while the CFL might be more susceptible to injury in dorsiflexion and pronation. Furthermore, in the case of surgical reconstruction the grafts used to reconstruct the two ligaments may need to be tensioned at different positions of the ankle in order to reproduce their natural in vivo function.

No MeSH data available.


Related in: MedlinePlus