Total Pageviews



Saturday, October 9, 2010

Accessory Navicular/Os Navicularis/Os Tibial Externum: Advice on Treatment

Vitals: 4,418 visits, 3,181 visitors, 86 countries, 34 followers Thank You!!

Sunset from my front lawn in San Francisco
Hi Dr. Blake,

I saw found your name through yelp, and I have been very impressed by your reviews. I wanted to get your opinion about surgical excision of an accessory navicular bone.
I'm a 27 year old male who is active with running and triathlons, and I'm also on my feet all day at work. I went in to my podiatrist with a complaint of pain at a bump on my medial arch that has been on and off for the past year. X-rays showed a rather large accessory navicular bone, and my podiatrist recommended removal of the bone and tacking down the posterior tibialis tendon to the true navicular. My pain level varies between 0 to 3 out of 10, and tends to flare up after running 3-4 miles or standing for 10+ hours. I have been forced to cut back on my running significantly as a result.

I was wondering what your experience and opinion is about surgical removal of an accessory navicular bone? Are there conservative measures that you feel may be successful? Or is surgery the best option?
Thank you, I appreciate you taking the time to read my email!


Dear Jon,

     Thanks for the email. The accessory navicular is also called "the second ankle bone", on the side of the foot as the arch, and rarely needs surgical excision. 10% of the adult population has it, and 30% of those have it on both sides. Being a very common weakness in the arch, and seeing thousands of patients with them, I have seen only a few go on to surgical excision. The posterior tibial tendon, the strongest tendon to support the arch and stop pronation, attaches into this side of the navicular. When you have an accessory navicular, you have a weakened arch by definition, but not one that is needs surgery that often. The source of the pain can be in the tendon, in the attachment of the accessory navicular into the navicular, and in the ligament underneath. The source of pain must be identified before you trade your pain with a surgical scar. A surgical scar has 10% chance of bothering you as much or more as your present symptoms. I am seeing on one hand, the gradual development of better surgical instrumention, and on the other hand, a problem with post operative care (less physical therapy being covered is a great concern particularly).

     With all that being said, let us start at the beginning. Golden Rule of Foot: Find Out What It Takes to Make The Patient Painfree, and then how to keep it that way. Before considering surgery, you should be on a very gradual progessive posterior tibial strengthening program. It is very reasonable to make your tendon 3 or 4 times stronger than it is now by exercises that isolate that tendon. In your honor, I will dedicate several posts over the next few weeks on this topic. Please see the links below on generalizations of strengthening. You will probably have to work with a good physical therapist to review all of the exercises and analyze where you are now and set up a reasonable plan. But, this is very do able.

    The next vital piece of the puzzle is anti-inflammatory. If you have pain, constant in nature, even at a 1 or 2 level, you should be doing a 10 minute ice pack twice daily to cool down the soreness, whether it hurts or not. Never run through pain (see the link below on Good Pain vs Bad Pain). If the soreness has been more up into the 3, 4, 5, 6 levels consistently, then you should use more activity modification, more icing, physical therapy, and perhaps medications. The program should be for 2 weeks longer than it takes to get the pain to 0 to 2 levels. Once you are at that level, you need to figure out how to keep it there. What does it takes?

    Normally while patients are dealing with strength and anti-inflammation measures, they are also working with biomechanics (arch support) and testing to discover the source of pain. The two standard tests are MRI and bone scan, but CT scan may have a place. The MRI is the best to see tendon or ligament damage (which may need surgery, but should be initally casted). The bone scan is best if you have a bone problem that may respond to removable cast and bone stimulator.  Oh, before I forget Jon, please copy a blow up photo of the accessary navicular (multiple views are encouraged) in the comment section or email to me, because it could give me more info.

     Getting the right orthotic devices can be hard (maximum support, but comfortable, is always a challenge), but it is vital to seeing first if surgery can be avoided, and second, helpful in the two years after surgery if needed that you have a weak arch. All the skills and understanding of principles you learn in this phase can be vital if surgery is indeed needed. Besides orthotic devices, arch taping (simple kinesio demonstrated in the photo above), power lacing (see link below), stable shoes, and training regimens, are all vital to keep you going.

     Jon, I hope this starts a journey of understanding so that if surgery is needed, you will have the best chance that it is successful.


  1. Thanks for the info! Just found out today I have this pesky second ankle, unusual I was told for a 45-year old woman. Treatment plan is to wear boot for a month, then get a custom orthotic. Have to stay off the elliptical in the meantime. :( Oh well....I'm all about avoiding surgery!


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.