1. What are the findings? Diagnosis?
There are fractures at the second through fifth proximal metatarsals. Mild lateral shift in alignment is seen at the second metatarsal fracture. There appears to be widening of the intermetatarsal space between the first and second metatarsal bases, however, alignment of the second metatarsal and medial cuneiform at the medial side is maintained. Mild dorsal shift at the second metatarsal fracture is also appreciated. No tarsometatarsal dislocation is present.
The findings are inconsistent with a Lisfranc fracture-dislocation and the diagnosis therefore is multiple traumatic metatarsal fractures. The distinction is an important one in the presence of midfoot fractures because of the possibility of ligamentous injury.
2. How does this injury commonly occur in a MVA?
Forced trauma of the foot while slamming hard on the brakes, with our without shearing or twisting forces.
3. Is any further imaging warranted?
Dislocations or subluxations may spontaneously reduce in non stress radiographs and therefore be hidden. Careful radiographic examination is warranted. If pain tolerance allows, standing ragiographs may be performed.
MRI may be used to assess the oblique ligament located between the medial cuneiform and second metatarsal base, whether the radigraphs are positive or equivocal. The transverse intertarsal ligaments located between the second through fifth metatarsal basis are also important to examine. In this case they are likely intact given the lack of dislocation or subluxation between the metatarsal bases. MRI may also be of use to rule out entrapment of tendons which may interfere with reduction.
The dorsalis pedis artery also passes between the bases of the first and second metatarsals and may be injured. If clinically indicated, additional imaging may be useful to assess the artery.
4. What is the appropriate follow up?
In instances involving minimal displacement, typically under 2-3 mm, treatment may involve conservative with closed reduction and casting. Cases with greater displacement or complexity may be treated with open reduction and internal fixation.
Complications are uncommon but include delayed or non union, avascular necrosis of the second metatarsal head secondary to injury to the dorsalis pedis and/or its branches, infection, persistent pain, and degenerative arthritis.
There are fractures at the second through fifth proximal metatarsals. Mild lateral shift in alignment is seen at the second metatarsal fracture. There appears to be widening of the intermetatarsal space between the first and second metatarsal bases, however, alignment of the second metatarsal and medial cuneiform at the medial side is maintained. Mild dorsal shift at the second metatarsal fracture is also appreciated. No tarsometatarsal dislocation is present.
The findings are inconsistent with a Lisfranc fracture-dislocation and the diagnosis therefore is multiple traumatic metatarsal fractures. The distinction is an important one in the presence of midfoot fractures because of the possibility of ligamentous injury.
2. How does this injury commonly occur in a MVA?
Forced trauma of the foot while slamming hard on the brakes, with our without shearing or twisting forces.
3. Is any further imaging warranted?
Dislocations or subluxations may spontaneously reduce in non stress radiographs and therefore be hidden. Careful radiographic examination is warranted. If pain tolerance allows, standing ragiographs may be performed.
MRI may be used to assess the oblique ligament located between the medial cuneiform and second metatarsal base, whether the radigraphs are positive or equivocal. The transverse intertarsal ligaments located between the second through fifth metatarsal basis are also important to examine. In this case they are likely intact given the lack of dislocation or subluxation between the metatarsal bases. MRI may also be of use to rule out entrapment of tendons which may interfere with reduction.
The dorsalis pedis artery also passes between the bases of the first and second metatarsals and may be injured. If clinically indicated, additional imaging may be useful to assess the artery.
4. What is the appropriate follow up?
In instances involving minimal displacement, typically under 2-3 mm, treatment may involve conservative with closed reduction and casting. Cases with greater displacement or complexity may be treated with open reduction and internal fixation.
Complications are uncommon but include delayed or non union, avascular necrosis of the second metatarsal head secondary to injury to the dorsalis pedis and/or its branches, infection, persistent pain, and degenerative arthritis.