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 ...

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2282 VII Imaging of the Musculoskeletal System A B D C Figure 47-88. Divergent Lisfranc dislocation in a 22-year-old who was driving on the highway when struck by another car going the wrong way. The patient also sustained a fracture of the contralateral femoral shaft. Anteroposterior (A) and oblique (B) radiographs demonstrate medial dislocation of the first metatarsal and lateral dislocation of the second through fourth metatarsals. The patient was taken to the operating room for open reduction and internal fixation of the femoral fracture with an intramedullary nail. Once the patient was fully anesthetized, the surgeon was able to apply longitudinal traction on the first ray and achieve closed anatomic reduction of the Lisfranc joint. C, Oblique port intra-operative radiograph. D, The patient returned to the operating room 1 week later, after the swelling had diminished, for elective fixation of the Lisfranc joint. is common for a base of the second metatarsal to be sheared off or avulsed. In some cases, axial oblique CT images can help to demonstrate subtle offsets at the tarsometatarsal joints, particularly when compared with the normal contralateral side (Fig. 47-89). In other cases, the dislocations along the Lisfranc joint may be manifest only when a lateral stress is applied to the forefoot. In these patients, the nonstressed CT scan may fail to demonstrate the degree of potential displacement (Fig. 47-90). • Arthritis 45 The hallmarks of osteoarthritis—nonuniform joint space narrowing accompanied by the formation of osteophytes, Ch047-A05375.indd 2282 9/9/2008 5:35:32 PM

47 Ankle and Foot 2283 47 LEFT LEFT A B C Figure 47-89. Subtle Lisfranc dislocation in a 39-year-old who fell backward down a 3-foot wall and injured the left foot. The patient bicycled home and continued to walk on this foot for 3 days before coming to the emergency department, concerned because the pain was not diminishing. Anteroposterior (A) and oblique (B) non–weight-bearing radiographs were obtained. Close scrutiny of the Lisfranc joint on the oblique view (dashed box) reveals small fractures off the bases of the second and first metatarsals (arrowheads). The Lisfranc joint appears anatomically aligned. The presence of the fragments along the Lisfranc joint raised the concern that this may represent a Lisfranc dislocation. C and D, CT scans were performed to assess the integrity of the tarsometatarsal joint. C, Axial oblique scan through both medial Lisfranc joints. In the normal right foot there is anatomic alignment across the first, second, and third cuneiform-metatarsal joints. In the injured left foot there is lateral subluxation of the first (white arrow) and third (black arrow) metatarsals as well as small fragments off the second metatarsal (white arrowhead) and second cuneiform (black arrowhead). D, Axial oblique scan, slightly more plantar and more angled than C, through the lateral tarsometatarsal joint. On the normal right side the articular surfaces of the fifth metatarsal (V) and the cuboid (Cu) are aligned (white arrows). On the left, the lateral corner of the fifth metatarsal (black arrow) is laterally displaced relative to the cuboid’s impacted lateral corner (open arrowhead). These findings confirmed that the patient had sustained a disruption of the Lisfranc joint, which was treated with a boot and non– weight bearing. D Ch047-A05375.indd 2283 9/9/2008 5:35:34 PM

2282 VII Imaging <strong>of</strong> the Musculoskeletal System<br />

A<br />

B<br />

D<br />

C<br />

Figure <strong>47</strong>-88. Divergent Lisfranc dislocation in a 22-year-old who was driving on the highway when struck by another car going the wrong way.<br />

The patient also sustained a fracture <strong>of</strong> the contralateral femoral shaft. Anteroposterior (A) <strong>and</strong> oblique (B) radiographs demonstrate medial<br />

dislocation <strong>of</strong> the first metatarsal <strong>and</strong> lateral dislocation <strong>of</strong> the second through fourth metatarsals. The patient was taken to the operating room for<br />

open reduction <strong>and</strong> internal fixation <strong>of</strong> the femoral fracture with an intramedullary nail. Once the patient was fully anesthetized, the surgeon was<br />

able to apply longitudinal traction on the first ray <strong>and</strong> achieve closed anatomic reduction <strong>of</strong> the Lisfranc joint. C, Oblique port intra-operative<br />

radiograph. D, The patient returned to the operating room 1 week later, after the swelling had diminished, for elective fixation <strong>of</strong> the Lisfranc joint.<br />

is common for a base <strong>of</strong> the second metatarsal to be<br />

sheared <strong>of</strong>f or avulsed. In some cases, axial oblique CT<br />

images can help to demonstrate subtle <strong>of</strong>fsets at the<br />

tarsometatarsal joints, particularly when compared with<br />

the normal contralateral side (Fig. <strong>47</strong>-89). In other cases,<br />

the dislocations along the Lisfranc joint may be manifest<br />

only when a lateral stress is applied to the forefoot. In these<br />

patients, the nonstressed CT scan may fail to demonstrate<br />

the degree <strong>of</strong> potential displacement (Fig. <strong>47</strong>-90).<br />

• Arthritis 45<br />

The hallmarks <strong>of</strong> osteoarthritis—nonuniform joint space<br />

narrowing accompanied by the formation <strong>of</strong> osteophytes,<br />

Ch0<strong>47</strong>-A05375.indd 2282<br />

9/9/2008 5:35:32 PM

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