Talar fractures are unfortunately all to common. Talar fractures can be quite debilitating and lead to a loss of career or limitations in activities. Talar fractures are a common sequelae of motor vehicle accidents and falls from a height. We see talar fractures in rock climbers and roofers.
One complication of a talar fracture is avascular necrosis (AVN). AVN occurs when the blood supply to the talus is disrupted. Avascular simply means no blood and necrosis means that the bone dies as a result of this loss of blood.
But AVN can also occur in the talus in the absence of trauma. I saw a case today of non-traumatic AVN in a pleasant 72 y/o housewife. She described a mild sprain several months ago but didn’t seem to relate the sprain to her current pain. Plain films were negative for change. MRI indicated extensive necrosis of the distal tibia and neck of the talus suggesting a dorsiflexion injury of the ankle.
AVN can occur at a number of locations in the body, most commonly the hip. Due to load bearing of the hip, fracture is a common outcome of AVN in the hip.
We know that the talus is particularly susceptible to AVN due to the fact that it is 3/5 covered with cartilage. This cartilage makes up the joint surfaces of the ankle and subtalar joints. And anywhere we find cartilage, we cannot have a blood vessel enter the bone. Therefore, the more cartilage, the less vascular inflow and increased risk for AVN.
But without a history of trauma, how does AVN occur? A direct correlation between steroid use and AVN of the hip is found in the literature. Why steroids? We’re not really sure. Occlusion by embolis is another possibility. But I think we have a lot to learn about the etiology of non-traumatic AVN.
We’ll keep this patient partial weight bearing in a walking cast and keep her on a walker. She knows that it’ll be a number of months before I feel comfortable with her bearing full weight on the foot. She also realizes that as the AVN progresses, the possibility of collapse of the talus ever present.
Jeffrey Oster, DPM
Medical Director
Myfootshop.com
Myfootshop.com foot and ankle blog 
I also have AVN in my talus..
but have not had any trauma.. the only difference between myself and the patient in question is I am only 23 years of age.. I have a 1cm degeration on the medial side of the talus, found by MRI. I am wondering the possiable treatment paths..
Lacy
Comment by Lacy — August 21, 2008 @ 5:09 pm
Hi Lacy,
Sounds like you’ve been doing your homework on the Internet? I think what you’ll find in most descriptions of AVN is a four stage process that begins with loss of blood flow, structural collapse of the bone and eventual rebuilding. Sound familiar?
The other thing about AVN is that each and every case is going to vary in it’s severity and rate with which it heals.
One of the constants with treating AVN is that you need to let the AVN run its’ course prior to trying to treat it. So you have to go through this long course of waiting prior to any attempt at surgical reconstruction. That waiting period can often be more than a year.
When did you first start to feel symptoms of pain or swelling? What kinds of treatment have you had so far?
Jeff
Comment by Jeffrey Oster, DPM — August 21, 2008 @ 7:26 pm
Hi
I was just diagnosed today with AVN. My doctor wants me to wear an ankle brace along with an injection of a steroid into the joint to relieve swelling so that the blood supply can try to get back into the bone. He told me is that does not work he will go in and drill small holes into the bone. He told me that if we do nothing the bone will just break down and really cause problems. Is my doctor doing the right thing?
Darin
Comment by Darin Osborne — September 13, 2008 @ 8:19 am
Hi Darin,
It’s a bit of a double edged sword int hat steroids are a documented contributing factor in AVN, but a lot of doc use them to manage the inflammation associated with AVN. Tread carefully with the steroid use, OK?
How’s it doing for you overall?
for more information on this topic, I’d suggest that you jump into our forum located at http://www.myfootshop.com/discussion.
Jeff
Comment by Jeffrey Oster, DPM — September 30, 2008 @ 12:21 am
My 13 year old daughter has AVN in her talus, with no known trauma (other than mild sprains from soccer). Her degradation is 3cm. She wears a brace and her activities are quite restricted. Her doctor doesn’t recommend any treatment. What’s your opinion about ankle allograft transplant? She’d love to play sports again…
Marie
Comment by Marie — September 30, 2008 @ 6:29 am
Hi Marie,
Tough call. The talus is just so darned fragile. I think the first issue would be how long the AVN has been present. If it lasted more than 12 months, I’d have to assume that grafting would be indicated.
Let’s jump over to the forum with this conversation. I try to keep clinical discussions in the forum so that we can get the input of others. My blog is just for ramblings of day to day issues in practice.
Go to The Foot Talk Forum and let’s talk a bit there.
Look forward to chatting.
Jeff
Comment by Jeffrey Oster, DPM — September 30, 2008 @ 6:57 am
Hi Jeff,
I had a talus fracture in mar2001 and aug2001 I was grafted and done subtalar partia fusion.
I again started getting severe pain and now doctors advise for complete fusion .
I’m 33 yrs old and hate to limp rest of my life with ankle fusion,
PL advise
Thanks,
Nayeem
Comment by Mohammed Nayeem — October 26, 2008 @ 9:58 am
Hi Nayeem,
Any chance we could talk in our forum located at http://www.myfootshop.com/discussion? I’m limited in what I can say here in the blog due to limitations on my medical liability coverage.
Jump into the forum when you get a chance and tell me a bit more about the ankle and what choices you’re looking at.
Jeff
Comment by Jeffrey Oster, DPM — November 28, 2008 @ 9:44 pm