Total Pageviews

Followers

Dr Blake's Book

Translate

Saturday, December 31, 2011

Sesamoid Injury: MRI evaluation

The following series of MRI images closes out my first full year as a blogger. I started in 2010 and still have not found my rhythm of sorts. I am amazed that the blog has hit 150,000 page views. Thank you readers.  I hope this blog has been helpful to many people and I will continue to work hard on the content in 2012. Happy New Year!! First some fireworks from the Hilton Hawaiian Village in Waikiki. 



Here the injured tibial sesamoid (aka medial sesamoid) under the first metatarsal shows up white on this T2 image MRI. The arrow points to the injured sesamoid on the bottom of the foot at the ball of the foot. The first metatarsal overlying the sesamoid is also inflamed  on its weight bearing surface making it difficult to walk. The same injury on the top of the joint can walk more easily. The the top and side of the first metatarsal intense soft tissue swelling is seen making it difficult to bend the joint. Sorry Jen!!


On this image, the normal fibular sesamoid (aka lateral sesamoid) shows up dark black. On this T2 imaging, normal bone, tendon, and ligaments are dark black. When they are injured, the normal healing process brings fluid into them and they get white reflecting that fluid. 


On this image, the bottom of the ball of the foot is sliced. The tibial sesamoid is seen white, and the fibular sesamoid black. The arrow points to the grayish fracture line running through the sesamoid.

This same image is shown to demonstrate the intense swelling near the fracture, which occurred many months ago. This swelling will be addressed with contrast bathing (see blog post) and icing during the day. Anti-inflammatory medications like Advil or Aleve are contra-indicated since they can slow bone healing. Jen may need a bone stimulator to help heal this bone which is a notorious slow healer. She has been placed in a removable cast with her orthotics to off weight the injured bone. 

Again the healthy fibular is highlighted by the arrow. Jen is upping her daily Vit D and Calcium. We are going to get a Bone Density Screen and Vit D3 blood levels. She has run low in the past. The injury occurred 6 months after childbirth and perhaps her estrogen levels were off. We need normal Vit D and estrogen to move calcium into bones. Even transient drops in these levels, at a time of increase activity, can produce a stress fracture. 


On this section, the top of the foot, especially the top of the big toe joint is sectioned. The arrow points to the intense swelling at the top of the joint making it impossible to bend her toe. The initial X-rays taken were negative for fracture, but stress fractures can be a hair line and never show up. Many patients have X-rays for sesamoid injuries read as negative correctly, but still may have a stress fracture. With sesamoid injuries, you have to treat the worse case scenario, a possible fracture unless an MRI or bone scan proves it is not a fracture. X-rays are not great indicators since the injury can be too subtle to pick up. Many stress fracture locations are probably fine if the patient does not know exactly if the bone is fractured or not. The patient is still treated until the symptoms go away. With sesamoid fractures, when the stress fracture is not picked up, there is a greater chance of surgery down the road. As of right now, I told Jen she has about a 10% chance of surgery 6 to 12 months from now. We will get a new MRI in 3 months to check healing. If improvement is noted, the odds for surgery go now. If no improvement is noted, the odds for surgery go up. 


This is a T1 image highlighting normal bone as white. The arrow points to the fracture line in the tibial sesamoid. The fracture is non displaced and has excellent healing potential. I tend to use bone stimulators when there is some displacement of the fracture pieces which could make healing slower or not occur at all. I love Smith and Nephew's Exogen Unit. It is used 20 minutes twice daily. 

This T1 image shows the tibial (medial) sesamoid surrounded by inflammation. The inflammation is a grayish cloud that can be seen on top of the joint also. The fracture line is seen along with other areas of the bone which are darkened indicating healing is active. Emphasis on healing!! 

This image shows the normal fibular sesamoid. The difference in the 2 sesamoids is quite distinct visually. 


This T2 image really shows the healthy top bone, and the inflamed angry mad sore unhappy discontented "difficult to get along with" bottom bone. Sorry the image is on its side. When the bottom (plantar) part of the bone is involved, weight bearing can be difficult and harmful. If I can not get her weight bearing comfortably, but I should if I am worth my salt, she would have to be non weight bearing. The Golden Rule of Foot: You must always create a pain free environment for injuries to heal. Even though levels 0 to 2 pain is still considered good pain, pain is different for different people. Jen has a high pain threshold, so her level 2 may be a 4 or 5 for someone else. I have to be more cautious and protective in a high pain threshold patient, than a low pain threshold patient like myself.


The fibular sesamoid and underlying tendon to the big toe look normal. 


This image shows the non displaced fracture line in the tibial sesamoid.


This T1 image shows the inflamed tibial sesamoid, and the inflamed bottom of the first metatarsal. The fibular sesamoid and all of the other metatarsals look very healthy. We can not rule out actual injury to the first metatarsal also, so I will be talking to Jen about getting a CT Scan in the New Year (less than 6 hours at the time of this typing). The CT Scan will only show bone and show me if there is anything more happening than just (poor choice of words) a sesamoid injury.

Jen, we have a little adventure ahead of us. Rich


3 comments:

  1. Dr. Blake! Thanks for posting and explaining the MRI of the sesamoid. I found this in search of deciding wether the cost of a MRI will be useful in aiding my tibial sesamoid fracture. I wish I had started doing research earlier. I am learning new things such as using the exogen bone stimulator twice a day instead of the recommended once a day.
    I did not see a Dr. for my foot until 3-4 months after the injury. My Dr. put me in an immobilization shoe (which i alternated wearing with a carbon fiber insert in cuter shoes) for 2 months. I had a prolo shot, then arfter 2 months recieved my exogen machine and vitamin prescription. she was going to let me go back to work (with continued immobilization) and made it sound like the 2 fractured peices had mended together on one side.
    I grew nervous and just got a 2nd opinion. When I looked at the x-ray...the tibial sesamoid looks like a pile of mush with no defined sides...YIKES!! He put me in a bigger CAM boot, prescribed a steriod, wants me off for another month as well as an MRI. Any suggestions you have for me?? How will a MRI help my treatment??
    Thanks! ....Discouraged in Texas Tiffany

    ReplyDelete
    Replies
    1. Tiffany, see my reply in my blog 4/26/12. Hope it helps you. Dr Rich Blake

      Delete
  2. Quite informative post! thank you for sharing this wonderful information with us!

    ReplyDelete

Thank you very much for leaving a comment. Due to my time restraints, some comments may not be answered.I will answer questions that I feel will help the community as a whole.. I can only answer medical questions in a general form. No specific answers can be given. Please consult a podiatrist, therapist, orthopedist, or sports medicine physician in your area for specific questions.