This case presents common bone contusion or injury from stress inversion injury that precedes actual Jones fracture. A case study is presented that will correlate radiographic and MRI findings. https://www.nhsheroes.co.uk/product-category/codeine/
A 34 year old female presents to the office on consultation on November 8th, 2006. She states that on October 14th, 2006, she was chasing her baby and inverted her foot during a fall over a baby toy. She went to the local Doctors Center and underwent x-rays that were inconclusive of fracture. She was given a shot of local steroid and placed on oral Ibuprofen. Crutches were dispensed and instructions to stay off work for one week.
She returned to work after being off the foot for one week and returned to her activity. Unfortunately, she continue to have pain and swelling to the region. She made an appointment to see her primary doctor who referred her to our office.
Clinically, she had localized swelling , but no signs of ecchymosis to the lateral aspect of the foot. There was pain on local stress inversion of the foot. Pain is focal directly to the fifth metatarsal base on palpation. The patient has no allergies and takes no medications regularly. She is active and healthy.
Radiographs were performed in the office which reveals a cystic change to the base of the fifth metatarsal consistent with hemorrhagic bone cyst. Two views obtained do confirm the presence of a hairline non-displaced fracture involving the very proximal aspect of the fifth metatarsal base. The fractures are non-displaced and do not appear to extend into the adjacent joint space within the cuboid and fifth bone.
MRI studies were ordered to rule out associated stress fracture or other pathology. High field 1.5 tesla MRI of the right foot with/without contrast revealed:
Multiplanar, multisequence images were obtained revealing, in the T1WI , diffuse focal area of low signal intensity involving the proximal aspect extending to the midshaft of the fifth metatarsal bone as well as the very proximal shaft of the fourth metatarsal and most distal aspect of the cuboid bone adjacent to the fourth and fifth metatarsal. In the respective T2 weighted IR images they appear as diffuse high signal intensity consistent with edema or hemorrhage secondary to the presence of bone contusion. We also observe the presence of a non-displaced hairline fracture involving the very proximal aspect of the fifth metatarsal bone near the base which is non-displaced. The remaining visualized bone structures show normal bone marrow signal intensity.
A closer look at the oblique plain film reveals a distinct area of stress fracture along the proximal base of the fifth metatarsal. This is much more obvious on this view than the lateral view above, which reveals a more contusion or cystic type look to the fracture. It is apparent that this is a 3 dimensional area of stress induced trauma to the base of the 5thmetatarsal, with hemorrhage extending almost to the lateral cortex of the fifth metatarsal.
The coronal STIR view on MRI is quite dramatic. It reveals an obvious fracture line directly across the base of the fifth metatarsal. The T2 image reveals increased focal uptake to the fracture site. It is interesting on this view that it actually appears the fracture is complete through the entire base of the 5thmetatarsal, suggesting a stage 2 type fracture that would require intramedullary fixation. (see my Simple Classification for Jones Fracture). An argument could be made for conservative casting versus intramedullary fixation. However, in this particular case, we opted on casting with complete non-weightbearing for 6 weeks.
I took this approach in consideration since the patient was weightbearing on this stress fracture two weeks after injury, and had not yet overtly fractured the base of the fifth metatarsal (Stage 3 fracture). Also, the close proximity of this fracture line of the styloid process and cuboid articulation with less than 1.5cm of the base would prove difficult for screw placement. Also, on the lateral radiograph, the orientation of the fracture appears to be in a dorsal distal to proximal plantar or oblique fashion. This also would make fixation difficult and probably unnecessary in this case. As you can see in this case, classification systems are nice, but each case is still individual and variations of fracture orientation will occur.
On T2 coronal,sagital and axial views, we can also see some contusion to the lateral border of the cuboid bone. In fact, as upper sagital sequencing progressed, there was actually some increased signal intensity on T2 imaging to th lateral body of the cuboid. On the axial views, there is also increased signal intensity on T2 imaging to the 4th metatarsal base as well. This reveals the extent of traumatic injury to this region.
This case highlights the importance of correlation studies using MRI with suspected contusion injuries of the fifth metatarsal base. This patient was seen in our office two weeks after initial injury and plain radiographs suspected injury and bone hemorrhage to the base of the fifth metatarsal. MRI confirmed not only bone hemorrhage along the base of the fifth metatarsal, but also an apparent stress fracture that was difficult to visualize initially on radiograph. In fact, most physicians would extrapolate stress fracture with bone calcification and sclerosing of the fracture site.
However, in this case, stress fracture was easily visualized on MRI coronal STIR imaging. This would also suggest, that using, for instance, the Torg Classification as described in an earlier article, is difficult to apply in this type of fracture. The Simple Classification described in an earlier article would suggest a Stage 2 stress fracture that could be fixated with intramedullary fixation to promote faster healing and stability. However, due to the close proximity of this fracture to the proximal cortex of the fifth metatarsal base and cuboid articulation, fixation would prove difficult. It was the authors opinion to institute casting in this case since the patient had been weightbearing for two weeks without progression to overt Stage 3 Jones fracture.