HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pearce, D. H. Articles by Daniels, T. R. Search for Related Content PubMed PubMed Citation Articles by Pearce, D. H. Articles by Daniels, T. R. Related Collections Musculoskeletal Radiology

Avascular Necrosis of the Talus: A Pictorial Essay¹

¹ From the Departments of Radiology (D.H.P., C.N.M.), Pathology (V.L.F.), and Orthopedic Surgery (T.R.D.), St Michael’s Hospital, University of Toronto, 30 Bond St, Toronto, Ontario, Canada M5B 1W8. Received April 29, 2004; revision requested June 3; final revision received August 18; accepted August 20. All authors have no financial relationships to disclose.

View larger version (78K): [in a new window]   Figure 1.  Lateral radiograph shows the normal skeletal anatomy of the foot and ankle. C = cuneiform bone, Cal = calcaneus, Cu = cuboid bone, F = fibula, M = metatarsal bones, N = navicular bone, Ph = phalanges, STJ = posterior facet of the subtalar joint, Tb = talar body, TD = talar dome, Th = talar head, Ti = tibia, Tn = talar neck.

 

View larger version (96K): [in a new window]   Figure 2a.  Coronal computed tomographic (CT) scan (a) and sagittal T1-weighted magnetic resonance (MR) image (b) demonstrate the normal skeletal anatomy of the foot and ankle. AJ = ankle joint, C = medial cuneiform bone, Cal = calcaneus, Cu = cuboid bone, F = fibula, N = navicular bone, STJ = subtalar joint, T = talus, TD = talar dome, Ti = tibia, TN = talar neck.

 

View larger version (157K): [in a new window]   Figure 2b.  Coronal computed tomographic (CT) scan (a) and sagittal T1-weighted magnetic resonance (MR) image (b) demonstrate the normal skeletal anatomy of the foot and ankle. AJ = ankle joint, C = medial cuneiform bone, Cal = calcaneus, Cu = cuboid bone, F = fibula, N = navicular bone, STJ = subtalar joint, T = talus, TD = talar dome, Ti = tibia, TN = talar neck.

 

View larger version (128K): [in a new window]   Figure 3a.  AVN of the talus. (3a) Lateral radiograph shows marked sclerosis of the talar dome and body (arrow). (3b) Radiograph (mortice view) shows marked sclerosis of the entire talar dome and throughout the lateral talar body (arrowheads).

 

View larger version (152K): [in a new window]   Figure 3b.  AVN of the talus. (3a) Lateral radiograph shows marked sclerosis of the talar dome and body (arrow). (3b) Radiograph (mortice view) shows marked sclerosis of the entire talar dome and throughout the lateral talar body (arrowheads).

 

View larger version (175K): [in a new window]   Figure 4.  Radiograph (mortice view) shows an area of increased opacity in the medial talar dome that extends laterally toward the lateral talar dome (arrowheads), a finding that represents an osteonecrotic segment.

 

View larger version (167K): [in a new window]   Figure 5.  Radiograph (mortice view) shows a lobulated subchondral radiolucent area extending into the talar body. This area represents peripheral sclerosis, which outlines a necrotic segment (black arrows). The 1-mm-wide depression in the articular surface of the medial third of the talar dome (white arrow) represents talar collapse.

 

View larger version (45K): [in a new window]   Figure 6a.  Drawings illustrate the blood supply of the talus. (a) Medial talar blood supply. The first branches of the posterior tibial artery are the posterior tubercle branches. More distally, the posterior tibial artery gives off the tarsal canal artery with its deltoid branches. This artery courses through the tarsal canal. (b) Lateral talar blood supply. The lateral tarsal artery connects the dorsalis pedis artery to the perforating peroneal artery. It also branches to form the tarsal sinus artery. (c) Inferior talar blood supply. The tarsal sinus artery and the tarsal canal artery form an anastomotic loop within the tarsal canal. (d) Posterior talar blood supply. The posterior tubercle branches of the posterior tibial artery and perforating peroneal artery supply the medial and lateral tubercles.

 

View larger version (46K): [in a new window]   Figure 6b.  Drawings illustrate the blood supply of the talus. (a) Medial talar blood supply. The first branches of the posterior tibial artery are the posterior tubercle branches. More distally, the posterior tibial artery gives off the tarsal canal artery with its deltoid branches. This artery courses through the tarsal canal. (b) Lateral talar blood supply. The lateral tarsal artery connects the dorsalis pedis artery to the perforating peroneal artery. It also branches to form the tarsal sinus artery. (c) Inferior talar blood supply. The tarsal sinus artery and the tarsal canal artery form an anastomotic loop within the tarsal canal. (d) Posterior talar blood supply. The posterior tubercle branches of the posterior tibial artery and perforating peroneal artery supply the medial and lateral tubercles.

 

View larger version (48K): [in a new window]   Figure 6c.  Drawings illustrate the blood supply of the talus. (a) Medial talar blood supply. The first branches of the posterior tibial artery are the posterior tubercle branches. More distally, the posterior tibial artery gives off the tarsal canal artery with its deltoid branches. This artery courses through the tarsal canal. (b) Lateral talar blood supply. The lateral tarsal artery connects the dorsalis pedis artery to the perforating peroneal artery. It also branches to form the tarsal sinus artery. (c) Inferior talar blood supply. The tarsal sinus artery and the tarsal canal artery form an anastomotic loop within the tarsal canal. (d) Posterior talar blood supply. The posterior tubercle branches of the posterior tibial artery and perforating peroneal artery supply the medial and lateral tubercles.

 

View larger version (40K): [in a new window]   Figure 6d.  Drawings illustrate the blood supply of the talus. (a) Medial talar blood supply. The first branches of the posterior tibial artery are the posterior tubercle branches. More distally, the posterior tibial artery gives off the tarsal canal artery with its deltoid branches. This artery courses through the tarsal canal. (b) Lateral talar blood supply. The lateral tarsal artery connects the dorsalis pedis artery to the perforating peroneal artery. It also branches to form the tarsal sinus artery. (c) Inferior talar blood supply. The tarsal sinus artery and the tarsal canal artery form an anastomotic loop within the tarsal canal. (d) Posterior talar blood supply. The posterior tubercle branches of the posterior tibial artery and perforating peroneal artery supply the medial and lateral tubercles.

 

View larger version (143K): [in a new window]   Figure 7a.  AVN of the talus in a 42-year-old man who was involved in a serious motor vehicle accident. (a) Axial CT scan through the talus shows diffuse sclerosis involving the majority of the talus (white arrows), with focal sparing of the lateral talar dome (black arrow). (b) Axial fat-saturated T2-weighted MR image shows diffuse high signal intensity in the majority of the talus. The lateral talar dome demonstrates normal bone marrow signal intensity (arrowheads), a finding that corresponds to the normal region seen at CT.

 

View larger version (137K): [in a new window]   Figure 7b.  AVN of the talus in a 42-year-old man who was involved in a serious motor vehicle accident. (a) Axial CT scan through the talus shows diffuse sclerosis involving the majority of the talus (white arrows), with focal sparing of the lateral talar dome (black arrow). (b) Axial fat-saturated T2-weighted MR image shows diffuse high signal intensity in the majority of the talus. The lateral talar dome demonstrates normal bone marrow signal intensity (arrowheads), a finding that corresponds to the normal region seen at CT.

 

View larger version (125K): [in a new window]   Figure 8a.  Osteonecrosis of the talus in a 51-year-old woman who had received a short course of prednisone. Axial (a) and coronal (b) CT scans through the right talus show a mixed hypoattenuating-sclerotic pattern along the medial half of the talar dome that is outlined by a serpiginous sclerotic line (arrows). The mixed imaging pattern is consistent with osteonecrosis.

 

View larger version (133K): [in a new window]   Figure 8b.  Osteonecrosis of the talus in a 51-year-old woman who had received a short course of prednisone. Axial (a) and coronal (b) CT scans through the right talus show a mixed hypoattenuating-sclerotic pattern along the medial half of the talar dome that is outlined by a serpiginous sclerotic line (arrows). The mixed imaging pattern is consistent with osteonecrosis.

 

View larger version (118K): [in a new window]   Figure 9a.  AVN of the talus in a 42-year-old man who was receiving prednisone for inflammatory bowel disease. (a) Lateral radiograph of the ankle shows a large, curvilinear radiolucent cleft extending from the talar dome into the talar body (arrowheads). In addition, there is serpiginous sclerosis within the distal tibia, calcaneus, and navicular bone (arrows). (b) Corresponding sagittal reconstructed image of the ankle from CT data shows a hypoattenuating area (arrowheads) surrounding a collapsed fragment of the talar dome. Areas of serpiginous sclerosis within the distal tibia, calcaneus, navicular bone, and base of the first metatarsal bone are again evident (arrows), findings that are consistent with medullary infarcts.

 

View larger version (105K): [in a new window]   Figure 9b.  AVN of the talus in a 42-year-old man who was receiving prednisone for inflammatory bowel disease. (a) Lateral radiograph of the ankle shows a large, curvilinear radiolucent cleft extending from the talar dome into the talar body (arrowheads). In addition, there is serpiginous sclerosis within the distal tibia, calcaneus, and navicular bone (arrows). (b) Corresponding sagittal reconstructed image of the ankle from CT data shows a hypoattenuating area (arrowheads) surrounding a collapsed fragment of the talar dome. Areas of serpiginous sclerosis within the distal tibia, calcaneus, navicular bone, and base of the first metatarsal bone are again evident (arrows), findings that are consistent with medullary infarcts.

 

View larger version (191K): [in a new window]   Figure 10a.  Posttraumatic osteonecrosis of the talus in a 42-year-old man who subsequently underwent below-the-knee amputation. (a) Sagittal T1-weighted MR image through the ankle demonstrates a serpiginous low-signal-intensity line in the talar dome (arrows). (b) Corresponding sagittal fat-saturated T2-weighted MR image shows a high-signal-intensity line in the talar dome (arrow) that outlines an avascular segment. (c) Low-power photomicrograph (original magnification, x25; WHO stain [hematoxylin, phloxine, saffron, alcian green]) helps confirm AVN of the talus. The cartilage is thinned and is stained green by the alcian green dye, which helps identify mucopolysaccharides. Note the paler than expected green staining of the articular cartilage of the talar dome (white arrow). Near the ankle joint, a curvilinear band of fibrous tissue (black arrows) appears as a pale pink band outlining the area of necrosis; trabeculae are preserved in this area. On the external aspect of the arch of fibrosis, there are coarser, thicker trabeculae, indicating that this area of the bone is viable and is capable of reaction. (d) High-power photomicrograph (original magnification, x250; WHO stain) of a decalcified section shows viable tibia (Ti) on one side of the joint and necrotic talus (Ta) on the other. The bone trabeculae on the viable (tibial) side show smooth endosteal contours (white arrows); the adipose tissue of the bone marrow shows a fine filiform pattern (white arrowheads). These findings contrast with the necrotic (talar) side of the joint: Here, the cartilage shows a more homogeneous pattern with loss of all cellular detail, the subjacent bone contains irregular and partly fragmented trabeculae (black arrows), and the bone marrow shows patchy eosinophilia (black arrowheads), which indicate that the fat has undergone degenerative change with saponification.

 

View larger version (201K): [in a new window]   Figure 10b.  Posttraumatic osteonecrosis of the talus in a 42-year-old man who subsequently underwent below-the-knee amputation. (a) Sagittal T1-weighted MR image through the ankle demonstrates a serpiginous low-signal-intensity line in the talar dome (arrows). (b) Corresponding sagittal fat-saturated T2-weighted MR image shows a high-signal-intensity line in the talar dome (arrow) that outlines an avascular segment. (c) Low-power photomicrograph (original magnification, x25; WHO stain [hematoxylin, phloxine, saffron, alcian green]) helps confirm AVN of the talus. The cartilage is thinned and is stained green by the alcian green dye, which helps identify mucopolysaccharides. Note the paler than expected green staining of the articular cartilage of the talar dome (white arrow). Near the ankle joint, a curvilinear band of fibrous tissue (black arrows) appears as a pale pink band outlining the area of necrosis; trabeculae are preserved in this area. On the external aspect of the arch of fibrosis, there are coarser, thicker trabeculae, indicating that this area of the bone is viable and is capable of reaction. (d) High-power photomicrograph (original magnification, x250; WHO stain) of a decalcified section shows viable tibia (Ti) on one side of the joint and necrotic talus (Ta) on the other. The bone trabeculae on the viable (tibial) side show smooth endosteal contours (white arrows); the adipose tissue of the bone marrow shows a fine filiform pattern (white arrowheads). These findings contrast with the necrotic (talar) side of the joint: Here, the cartilage shows a more homogeneous pattern with loss of all cellular detail, the subjacent bone contains irregular and partly fragmented trabeculae (black arrows), and the bone marrow shows patchy eosinophilia (black arrowheads), which indicate that the fat has undergone degenerative change with saponification.

 

View larger version (146K): [in a new window]   Figure 10c.  Posttraumatic osteonecrosis of the talus in a 42-year-old man who subsequently underwent below-the-knee amputation. (a) Sagittal T1-weighted MR image through the ankle demonstrates a serpiginous low-signal-intensity line in the talar dome (arrows). (b) Corresponding sagittal fat-saturated T2-weighted MR image shows a high-signal-intensity line in the talar dome (arrow) that outlines an avascular segment. (c) Low-power photomicrograph (original magnification, x25; WHO stain [hematoxylin, phloxine, saffron, alcian green]) helps confirm AVN of the talus. The cartilage is thinned and is stained green by the alcian green dye, which helps identify mucopolysaccharides. Note the paler than expected green staining of the articular cartilage of the talar dome (white arrow). Near the ankle joint, a curvilinear band of fibrous tissue (black arrows) appears as a pale pink band outlining the area of necrosis; trabeculae are preserved in this area. On the external aspect of the arch of fibrosis, there are coarser, thicker trabeculae, indicating that this area of the bone is viable and is capable of reaction. (d) High-power photomicrograph (original magnification, x250; WHO stain) of a decalcified section shows viable tibia (Ti) on one side of the joint and necrotic talus (Ta) on the other. The bone trabeculae on the viable (tibial) side show smooth endosteal contours (white arrows); the adipose tissue of the bone marrow shows a fine filiform pattern (white arrowheads). These findings contrast with the necrotic (talar) side of the joint: Here, the cartilage shows a more homogeneous pattern with loss of all cellular detail, the subjacent bone contains irregular and partly fragmented trabeculae (black arrows), and the bone marrow shows patchy eosinophilia (black arrowheads), which indicate that the fat has undergone degenerative change with saponification.

 

View larger version (124K): [in a new window]   Figure 10d.  Posttraumatic osteonecrosis of the talus in a 42-year-old man who subsequently underwent below-the-knee amputation. (a) Sagittal T1-weighted MR image through the ankle demonstrates a serpiginous low-signal-intensity line in the talar dome (arrows). (b) Corresponding sagittal fat-saturated T2-weighted MR image shows a high-signal-intensity line in the talar dome (arrow) that outlines an avascular segment. (c) Low-power photomicrograph (original magnification, x25; WHO stain [hematoxylin, phloxine, saffron, alcian green]) helps confirm AVN of the talus. The cartilage is thinned and is stained green by the alcian green dye, which helps identify mucopolysaccharides. Note the paler than expected green staining of the articular cartilage of the talar dome (white arrow). Near the ankle joint, a curvilinear band of fibrous tissue (black arrows) appears as a pale pink band outlining the area of necrosis; trabeculae are preserved in this area. On the external aspect of the arch of fibrosis, there are coarser, thicker trabeculae, indicating that this area of the bone is viable and is capable of reaction. (d) High-power photomicrograph (original magnification, x250; WHO stain) of a decalcified section shows viable tibia (Ti) on one side of the joint and necrotic talus (Ta) on the other. The bone trabeculae on the viable (tibial) side show smooth endosteal contours (white arrows); the adipose tissue of the bone marrow shows a fine filiform pattern (white arrowheads). These findings contrast with the necrotic (talar) side of the joint: Here, the cartilage shows a more homogeneous pattern with loss of all cellular detail, the subjacent bone contains irregular and partly fragmented trabeculae (black arrows), and the bone marrow shows patchy eosinophilia (black arrowheads), which indicate that the fat has undergone degenerative change with saponification.

 

View larger version (34K): [in a new window]   Figure 11a.  Drawings illustrate the Hawkins classification system for talar neck fractures. (a) Hawkins type I fracture is a nondisplaced fracture of the talar neck without dislocation. (b) Hawkins type II fracture is a displaced fracture through the talar neck with subluxation or dislocation of the subtalar joint. (c) Hawkins type III fracture is a displaced fracture through the talar neck with dislocation of the talar body from the subtalar and ankle joints. (d) Hawkins type IV fracture is a fracture through the talar neck with displacement of the talar head as well as subluxation or dislocation of the subtalar, tibiotalar, and talonavicular joints.

 

View larger version (35K): [in a new window]   Figure 11b.  Drawings illustrate the Hawkins classification system for talar neck fractures. (a) Hawkins type I fracture is a nondisplaced fracture of the talar neck without dislocation. (b) Hawkins type II fracture is a displaced fracture through the talar neck with subluxation or dislocation of the subtalar joint. (c) Hawkins type III fracture is a displaced fracture through the talar neck with dislocation of the talar body from the subtalar and ankle joints. (d) Hawkins type IV fracture is a fracture through the talar neck with displacement of the talar head as well as subluxation or dislocation of the subtalar, tibiotalar, and talonavicular joints.

 

View larger version (40K): [in a new window]   Figure 11c.  Drawings illustrate the Hawkins classification system for talar neck fractures. (a) Hawkins type I fracture is a nondisplaced fracture of the talar neck without dislocation. (b) Hawkins type II fracture is a displaced fracture through the talar neck with subluxation or dislocation of the subtalar joint. (c) Hawkins type III fracture is a displaced fracture through the talar neck with dislocation of the talar body from the subtalar and ankle joints. (d) Hawkins type IV fracture is a fracture through the talar neck with displacement of the talar head as well as subluxation or dislocation of the subtalar, tibiotalar, and talonavicular joints.

 

View larger version (37K): [in a new window]   Figure 11d.  Drawings illustrate the Hawkins classification system for talar neck fractures. (a) Hawkins type I fracture is a nondisplaced fracture of the talar neck without dislocation. (b) Hawkins type II fracture is a displaced fracture through the talar neck with subluxation or dislocation of the subtalar joint. (c) Hawkins type III fracture is a displaced fracture through the talar neck with dislocation of the talar body from the subtalar and ankle joints. (d) Hawkins type IV fracture is a fracture through the talar neck with displacement of the talar head as well as subluxation or dislocation of the subtalar, tibiotalar, and talonavicular joints.

 

View larger version (90K): [in a new window]   Figure 12a.  AVN of the talus in a 33-year-old man with a talar neck fracture. (a) Coronal CT scan through the talar dome shows an irregular, approximately 1-cm-thick region of subchondral sclerosis spanning the entire width of the dome (arrows). (b) Corresponding coronal fat-saturated T2-weighted MR image through the talus shows normal subchondral signal intensity across the talar dome (arrows) and high signal intensity throughout the talar body. (c) Coronal follow-up CT scan obtained 5 months later shows a region of subchondral sclerosis (arrows) that is unchanged from the corresponding area seen in a.

 

View larger version (121K): [in a new window]   Figure 12b.  AVN of the talus in a 33-year-old man with a talar neck fracture. (a) Coronal CT scan through the talar dome shows an irregular, approximately 1-cm-thick region of subchondral sclerosis spanning the entire width of the dome (arrows). (b) Corresponding coronal fat-saturated T2-weighted MR image through the talus shows normal subchondral signal intensity across the talar dome (arrows) and high signal intensity throughout the talar body. (c) Coronal follow-up CT scan obtained 5 months later shows a region of subchondral sclerosis (arrows) that is unchanged from the corresponding area seen in a.

 

View larger version (83K): [in a new window]   Figure 12c.  AVN of the talus in a 33-year-old man with a talar neck fracture. (a) Coronal CT scan through the talar dome shows an irregular, approximately 1-cm-thick region of subchondral sclerosis spanning the entire width of the dome (arrows). (b) Corresponding coronal fat-saturated T2-weighted MR image through the talus shows normal subchondral signal intensity across the talar dome (arrows) and high signal intensity throughout the talar body. (c) Coronal follow-up CT scan obtained 5 months later shows a region of subchondral sclerosis (arrows) that is unchanged from the corresponding area seen in a.

 

View larger version (95K): [in a new window]   Figure 13a.  AVN of the anterior talus in a 33-year-old man injured in a motor vehicle accident. (a) Axial CT scan through the talar dome reveals focal sclerosis in the anterior part of the dome (arrows), a finding that corresponds to an osteonecrotic segment. The posterior two-thirds of the dome shows normal bone marrow attenuation, which correlates with normal attenuation in the fibula. (b) Corresponding fat-saturated T2-weighted MR image shows diffuse increased signal intensity in the posterior two-thirds of the dome and normal bone marrow signal intensity in the anterior third. A serpiginous line separates these two regions (arrows).

 

View larger version (148K): [in a new window]   Figure 13b.  AVN of the anterior talus in a 33-year-old man injured in a motor vehicle accident. (a) Axial CT scan through the talar dome reveals focal sclerosis in the anterior part of the dome (arrows), a finding that corresponds to an osteonecrotic segment. The posterior two-thirds of the dome shows normal bone marrow attenuation, which correlates with normal attenuation in the fibula. (b) Corresponding fat-saturated T2-weighted MR image shows diffuse increased signal intensity in the posterior two-thirds of the dome and normal bone marrow signal intensity in the anterior third. A serpiginous line separates these two regions (arrows).

 

View larger version (136K): [in a new window]   Figure 14a.  Collapse and fragmentation of the talus in a 61-year-old man who had sustained minor trauma. (a) Coronal CT scan of the right ankle shows collapse of the articular surface of the talar dome (white arrows) and a vertical split fracture extending from the talar dome into the subtalar joint (black arrow). In addition, there is a curvilinear sclerotic line within the talar body (arrowheads) that represents necrotic bone. (b) Corresponding axial CT scan through the talar dome shows linear fractures through the posterior aspect of the dome (black arrows). The bone attenuation of the talar dome looks diffusely increased compared with that of the distal tibia and fibula. In addition, there is a small, ossific hyperattenuating area at the lateral aspect of the talus (white arrow), likely due to prior trauma.

 

View larger version (127K): [in a new window]   Figure 14b.  Collapse and fragmentation of the talus in a 61-year-old man who had sustained minor trauma. (a) Coronal CT scan of the right ankle shows collapse of the articular surface of the talar dome (white arrows) and a vertical split fracture extending from the talar dome into the subtalar joint (black arrow). In addition, there is a curvilinear sclerotic line within the talar body (arrowheads) that represents necrotic bone. (b) Corresponding axial CT scan through the talar dome shows linear fractures through the posterior aspect of the dome (black arrows). The bone attenuation of the talar dome looks diffusely increased compared with that of the distal tibia and fibula. In addition, there is a small, ossific hyperattenuating area at the lateral aspect of the talus (white arrow), likely due to prior trauma.

 

View larger version (136K): [in a new window]   Figure 15a.  Severe AVN of the talus with collapse of the talar dome. (a) Coronal CT scan through the talus shows a large hypoattenuating area surrounding an osteonecrotic segment of the medial talar dome, with a 1-mm articular step-off due to collapse of the medial articular surface (arrows). (b) Axial CT scan through the talar dome clearly depicts the large osteonecrotic segment (arrows), a finding that corresponds to the collapsed fragment seen in a.

 

View larger version (126K): [in a new window]   Figure 15b.  Severe AVN of the talus with collapse of the talar dome. (a) Coronal CT scan through the talus shows a large hypoattenuating area surrounding an osteonecrotic segment of the medial talar dome, with a 1-mm articular step-off due to collapse of the medial articular surface (arrows). (b) Axial CT scan through the talar dome clearly depicts the large osteonecrotic segment (arrows), a finding that corresponds to the collapsed fragment seen in a.

 

View larger version (74K): [in a new window]   Figure 16.  Bilateral AVN of the talus in an 18-year-old man who had undergone renal transplantation. Coronal CT scan of both ankles shows collapse of the articular surface of the lateral talar domes bilaterally (arrows), with underlying mixed hypoattenuating-sclerotic regions of necrotic subchondral bone.

 

View larger version (112K): [in a new window]   Figure 17a.  AVN of the talus in a female patient who had undergone renal transplantation. (a) Lateral radiograph of the right ankle shows diffuse sclerosis of the entire talus due to AVN, with sparing of the superior aspect of the talar head (white arrow). The inferior aspect of the talus shows irregular radiolucency (black arrows), with severe narrowing and anterior subluxation of the subtalar joint. (b) Coronal CT scan through the ankle shows sclerosis of the talar dome due to necrosis, along with multiple cystic hypoattenuating areas and fragmentation of the inferior articular surface of the talus (arrows). Note also the severe narrowing of the subtalar joint.

 

View larger version (113K): [in a new window]   Figure 17b.  AVN of the talus in a female patient who had undergone renal transplantation. (a) Lateral radiograph of the right ankle shows diffuse sclerosis of the entire talus due to AVN, with sparing of the superior aspect of the talar head (white arrow). The inferior aspect of the talus shows irregular radiolucency (black arrows), with severe narrowing and anterior subluxation of the subtalar joint. (b) Coronal CT scan through the ankle shows sclerosis of the talar dome due to necrosis, along with multiple cystic hypoattenuating areas and fragmentation of the inferior articular surface of the talus (arrows). Note also the severe narrowing of the subtalar joint.

 

View larger version (136K): [in a new window]   Figure 18a.  Hawkins sign in a female patient who had undergone external and internal fixation of a complex pilon fracture. Mortice-view (a) and lateral (b) radiographs of the ankle reveal striking subchondral radiolucency (arrowheads in a, arrows in b), a finding that indicates talar viability.

 

View larger version (110K): [in a new window]   Figure 18b.  Hawkins sign in a female patient who had undergone external and internal fixation of a complex pilon fracture. Mortice-view (a) and lateral (b) radiographs of the ankle reveal striking subchondral radiolucency (arrowheads in a, arrows in b), a finding that indicates talar viability.

 

View larger version (110K): [in a new window]   Figure 19.  Hawkins sign in a 27-year-old man who had undergone open reduction internal fixation for injuries sustained in a motorcycle accident. Radiograph (mortice view) shows a thin subchondral area of radiolucency involving the entire talar dome and lateral talar gutter (arrowheads), a finding that signifies talar viability and excludes future development of AVN.

 

---

HOME

HELP

FEEDBACK

SUBSCRIPTIONS

ARCHIVE

SEARCH

TABLE OF CONTENTS

RADIOGRAPHICS

RADIOLOGY

RSNA JOURNALS ONLINE

Copyright © 2005 by the Radiological Society of North America.