Ankle and Foot 47 - Department of Radiology - University of ...
Ankle and Foot 47 - Department of Radiology - University of ... Ankle and Foot 47 - Department of Radiology - University of ...
2228 VII Imaging of the Musculoskeletal System • Ankle Ligaments 14 There are three sets of ligaments around the ankle joint. Laterally there are the syndesmotic ligaments and the lateral capsular ligaments. The syndesmotic ligaments consist of the thin anterior tibiofibular ligament and the broader posterior tibiofibular ligament. These ligaments are typically best seen in the straight axial plane (Fig. 47-29A), although they may be seen in the coronal plane if a single image serendipitously cuts though one (Fig. 47-29C). It is these syndesmotic ligaments that are disrupted in a Weber type C ankle fracture (see Fig. 47-60C). The lateral capsular ligaments consist of the thin anterior talofibular ligament and the broader posterior talofibular ligament, both of which are transversely oriented and thus best seen in the straight axial plane (Fig. 47-29B), and the longitudinally oriented calcaneofibular ligament, best seen in the coronal plane (Fig. 47-29D). Of the lateral ankle ligaments, the anterior ones are more subject than the posterior ones to tearing from twisting injuries (Fig. 47-30). A B C D Figure 47-29. The normal lateral ankle ligaments. These are all T1-weighted images obtained using a high-resolution 512 acquisition matrix, in the same normal volunteer as in Figure 47-10. A, Axial image through the bottom of the syndesmosis shows the two syndesmotic ligaments: the anterior tibiofibular ligament (ATiFL; white arrow) and the posterior tibiofibular ligament (PTiFL; black arrow). B, Axial image two slices distal to A, through the top of the talar dome, shows two of the three lateral capsular ligaments: the anterior talofibular ligament (ATaFL; white arrowhead) and the posterior talofibular ligament (PTaFL; black arrowhead). C, Coronal image through the back of the ankle joint shows the PTiFL (black arrow) running between the posterior malleolus of the talus and the fibula. D, Coronal image two slices anterior to C shows the PTaFL (black arrowhead) running between the back of the talus and the fibula. Also seen is a portion of the third of the three lateral capsular ligaments, the calcaneofibular ligament (CFL; gray arrowhead). Ch047-A05375.indd 2228 9/9/2008 5:33:57 PM
47 Ankle and Foot 2229 47 Figure 47-30. Tears of the anterior lateral ankle ligaments in a 47-year-old. Straight axial protondensity (PD)–weighted (A) and T2-weighted fatsuppressed (B) images through the syndesmosis show disruption of the anterior tibiofibular ligament (arrow). Straight axial PD-weighted (C) and T2-weighted fatsuppressed (D) images through the top of the ankle mortise show an interruption (arrowhead) of the anterior talofibular ligament. A B C D Medially, the ankle joint is stabilized by a group of ligaments that fan out from the distal tip of the medial malleolus in a triangular configuration and collectively are called the deltoid ligament. When viewed in the coronal plane (Fig. 47-31), the deltoid ligament can be seen to consist of deep fibers that insert on the medial process of the talus and superficial fibers that insert on the calcaneus at the sustentaculum tali. Injuries of the deltoid ligament tend to be sprains* rather than complete ruptures, although they may be accompanied by bone marrow edema (Fig. 47-32) or even avulsion fractures. Unlike the ankle tendons, which when visualized by MRI can be followed over a series of sequential slices in several planes, the ankle ligaments are usually seen on only *”Sprains” are defined as stretching or tearing of ligaments and are due to twisting injuries. “Strains” are defined as stretching or tearing of muscles, often at the musculotendinous junction, and are caused by sudden and powerful contractions or from overuse. one or two slices in a single imaging plane. And when they are seen in a piecemeal fashion on two images, it can be difficult to determine whether the two halves of the ligament are continuous. Certainly, seeing fluid extending through or around the ankle ligament helps confirm the diagnosis of a tear, but at the UW our sports medicine clinicians and orthopedic surgeons do not use MRI to evaluate the ankle ligaments. They rely on physical examination, and sometimes stress radiographs, to assess the functional integrity of the ankle ligaments, ordering MRI primarily for the bones and tendons. There are many accessory ossicles that can be present throughout the skeleton, and these are well documented in the encyclopedic text by Keats. 27 Many of these normal variants can be found in the feet. Three of the most commonly found accessory ossicles in the feet are the os trigonum posterior to the talus, the accessory navicular medial to the navicular bone, and the os peroneum plantar to the calcaneocuboid joint. Although in the vast majority of people these are nothing more than asymptomatic inci- Ch047-A05375.indd 2229 9/9/2008 5:34:00 PM
- Page 1 and 2: Ken L. Schreibman Richard Bruce Ank
- Page 3 and 4: 47 Ankle and Foot 2209 47 Figure 47
- Page 5 and 6: 47 Ankle and Foot 2211 47 A B C Fig
- Page 7 and 8: 47 Ankle and Foot 2213 47 A B C D E
- Page 9 and 10: 47 Ankle and Foot 2215 47 A B C Fig
- Page 11 and 12: 47 Ankle and Foot 2217 47 Figure 47
- Page 13 and 14: 47 Ankle and Foot 2219 47 A B Figur
- Page 15 and 16: 47 Ankle and Foot 2221 47 Figure 47
- Page 17 and 18: 47 Ankle and Foot 2223 47 Figure 47
- Page 19 and 20: 47 Ankle and Foot 2225 47 A B C Fig
- Page 21: 47 Ankle and Foot 2227 47 J K L M N
- Page 25 and 26: 47 Ankle and Foot 2231 47 A B Figur
- Page 27 and 28: A C E B D F Figure 47-36. Accessory
- Page 29 and 30: 47 Ankle and Foot 2235 47 A B Figur
- Page 31 and 32: 47 Ankle and Foot 2237 47 Figure 47
- Page 33 and 34: 47 Ankle and Foot 2239 47 Figure 47
- Page 35 and 36: 47 Ankle and Foot 2241 47 Figure 47
- Page 37 and 38: 47 Ankle and Foot 2243 47 A Ankle/d
- Page 39 and 40: 47 Ankle and Foot 2245 47 A Figure
- Page 41 and 42: 47 Ankle and Foot 2247 47 ankle ten
- Page 43 and 44: 47 Ankle and Foot 2249 47 Figure 47
- Page 45 and 46: 47 Ankle and Foot 2251 47 A B C Fig
- Page 47 and 48: 47 Ankle and Foot 2253 47 Figure 47
- Page 49 and 50: 47 Ankle and Foot 2255 47 A B C D F
- Page 51 and 52: 47 Ankle and Foot 2257 47 A B C Fig
- Page 53 and 54: A B 47 Ankle and Foot 2259 47 Figur
- Page 55 and 56: 47 Ankle and Foot 2261 47 A C B D F
- Page 57 and 58: A B 47 Ankle and Foot 2263 47 Figur
- Page 59 and 60: 47 Ankle and Foot 2265 47 Figure 47
- Page 61 and 62: 47 Ankle and Foot 2267 47 Figure 47
- Page 63 and 64: • Calcaneal Fractures 6,18,33 47
- Page 65 and 66: 47 Ankle and Foot 2271 47 H J I LPT
- Page 67 and 68: 47 Ankle and Foot 2273 47 LPT N APC
- Page 69 and 70: 47 Ankle and Foot 2275 47 E F G H F
- Page 71 and 72: 47 Ankle and Foot 2277 47 Figure 47
2228 VII Imaging <strong>of</strong> the Musculoskeletal System<br />
• <strong>Ankle</strong> Ligaments 14<br />
There are three sets <strong>of</strong> ligaments around the ankle joint.<br />
Laterally there are the syndesmotic ligaments <strong>and</strong> the<br />
lateral capsular ligaments. The syndesmotic ligaments<br />
consist <strong>of</strong> the thin anterior tibi<strong>of</strong>ibular ligament <strong>and</strong> the<br />
broader posterior tibi<strong>of</strong>ibular ligament. These ligaments<br />
are typically best seen in the straight axial plane (Fig.<br />
<strong>47</strong>-29A), although they may be seen in the coronal<br />
plane if a single image serendipitously cuts though one<br />
(Fig. <strong>47</strong>-29C). It is these syndesmotic ligaments that are<br />
disrupted in a Weber type C ankle fracture (see Fig.<br />
<strong>47</strong>-60C).<br />
The lateral capsular ligaments consist <strong>of</strong> the thin anterior<br />
tal<strong>of</strong>ibular ligament <strong>and</strong> the broader posterior tal<strong>of</strong>ibular<br />
ligament, both <strong>of</strong> which are transversely oriented <strong>and</strong><br />
thus best seen in the straight axial plane (Fig. <strong>47</strong>-29B), <strong>and</strong><br />
the longitudinally oriented calcane<strong>of</strong>ibular ligament, best<br />
seen in the coronal plane (Fig. <strong>47</strong>-29D).<br />
Of the lateral ankle ligaments, the anterior ones are<br />
more subject than the posterior ones to tearing from twisting<br />
injuries (Fig. <strong>47</strong>-30).<br />
A<br />
B<br />
C<br />
D<br />
Figure <strong>47</strong>-29. The normal lateral ankle ligaments. These are all T1-weighted images obtained using a high-resolution 512 acquisition matrix, in<br />
the same normal volunteer as in Figure <strong>47</strong>-10. A, Axial image through the bottom <strong>of</strong> the syndesmosis shows the two syndesmotic ligaments: the<br />
anterior tibi<strong>of</strong>ibular ligament (ATiFL; white arrow) <strong>and</strong> the posterior tibi<strong>of</strong>ibular ligament (PTiFL; black arrow). B, Axial image two slices distal to A,<br />
through the top <strong>of</strong> the talar dome, shows two <strong>of</strong> the three lateral capsular ligaments: the anterior tal<strong>of</strong>ibular ligament (ATaFL; white arrowhead)<br />
<strong>and</strong> the posterior tal<strong>of</strong>ibular ligament (PTaFL; black arrowhead). C, Coronal image through the back <strong>of</strong> the ankle joint shows the PTiFL (black<br />
arrow) running between the posterior malleolus <strong>of</strong> the talus <strong>and</strong> the fibula. D, Coronal image two slices anterior to C shows the PTaFL (black<br />
arrowhead) running between the back <strong>of</strong> the talus <strong>and</strong> the fibula. Also seen is a portion <strong>of</strong> the third <strong>of</strong> the three lateral capsular ligaments, the<br />
calcane<strong>of</strong>ibular ligament (CFL; gray arrowhead).<br />
Ch0<strong>47</strong>-A05375.indd 2228<br />
9/9/2008 5:33:57 PM
Change language