It is 2am and there is a trauma patient in the resus area. Primary survey does not reveal any injuries. On secondary survey, you note that the patient has a swollen left foot and your next step is obviously to x-ray the area of interest to look for any fractures. In the meantime patient wants to know if he can be discharged as he has to fly out to a remote area for work soon. The x-rays are here. Would you let him go? What do the x-rays show?
The x-ray shows Lisfranc’s fracture dislocation. There is lateral subluxation of 2nd to 5th metatarsal bases. There is an avulsion fracture of base of 2nd metatarsal. The cuboid is also fractured. The lateral view shows a small step deformity at the base of metatarsals.
Normally, in the AP view of the foot, medial margin of the 2nd metatarsal should align with the medial margin of the intermediate cuneifom bone as shown below (red line).
Normally in the oblique view, medial margin of the 3rd metatarsal should align with the medial margin of the lateral cuneiform as shown below (blue line).
Compare the lines in Lisfranc’s fracture dislocation below. The AP view shows significant displacement of the 2nd metatarsal base and the oblique view shows some displacement of the 3rd metatarsal base.
Do you need to ring ortho at 3 am? Not unless there is associated neurovascular injury (dorsalis pedis) or evidence of compartment syndrome. But definitely at 7am.
An interesting clinical sign that may be seen in a Lisfranc’s injury is plantar ecchymosis sign as shown below.
(Plantar ecchymosis sign, image courtesy www.orthopaedia.com)[/peekaboo_content]
Plain xray of the left foot in two projections, AP and lateral.
Adequate exposure and quality
Markedly widening of the space between the base of the first and second metatarsal bones, about 4mm, with lateral type (divergent) dislocation of the lateral 4 metatarsal bones.
Fractured medial cuneiform and likely the lateral cuneiform as well.
Soft tissue edema
No other bone injuries
Lateral film shows no significant abnormalities.
Significant left foot xray findings in the form of widening of the first metatarsal and tarso metatarsal joint which is highly suggestive of Lis franc joint # dislocation.
In the setting of trauma of this patient:
1. Painful distracting injury, should not clear C spine clinically.
2. Significant force, look for other injuries.
3. Foot threatening injury, significant morbidity associated with this type of injury. Check neurovascularity. Therefore, the condition should be explained to the patient in details.
2. Back slab & RICE
3. CT foot
4. Admission & Ortho consultation, emergency .
Thank you for your extensive coverage of Lisfranc`s.
On the CT scans,this patient had associated cuboid and medial cuneiform fractures.
C Spine clearance in the right context though. If the injury is secondary to fall of heavy object on the foot, I wouldn`t chase the c spine for a fracture. And in regards to mechanism of Lisfranc`s it is not always high impact injury that causes it. In people who sustain simple plantar flexion injuries, the tarsometatarsal ligaments can `snap` and cause Lisfranc`s.
Tethering/tenting of the skin on the dorsum of foot is another indication for emergent reduction. In the absence of any neurovascular, fascial compartment or pressure area catastrophies, I do not think orthopaedic surgeons are going to rush the patient to theatre at 3 am!
Thanks for your thoughts.
1. Mechanism of injury: you are right it can result from forced planterflexion. However, given the stem trauma I presumed multisystem trauma. Just trying to make the answer exam palatable
2. Main aim of admission is RICE to prevent further tissue swelling/compartment syndrome, not necessary ortho intervention per say.
Thanks once again 🙂