Recently, I’ve had two patients with “sinus tarsitis”, something I’ve experienced as well. It’s a dull pain on the outside of the lower ankle. There is a dimple just below and in front of your outer ankle bone. This is the “sinus tarsus”. Hence, when inflamed: sinus tarsitis. It can be caused by trauma such as an ankle sprain, or it can occur without any apparent cause. It’s seen more in middle age persons. It actually involves joints of the lower ankle that are inflamed. It usually is a transient or temporary arthritis, but in rare cases a more enduring arthritis persists. Sinus tarsitis affected me without any apparent cause. Inbetween marathons I was concerned. X-rays and an MRI confirmed some early arthritic joint changes and inflammation of the sinus tarsus. I gave myself a shot of short-acting cortisone (doctors can be the worse patients). That didn’t help very much after the numbness wore off. Perhaps my angle of entry was off so I had a friend physician give me a SECOND shot a few weeks later (he used was a longer acting cortisone). I dug out my harder orthotics to use also. This was my good structural foot so I thought. The current standing X-ray showed otherwise. So I was not active for a couple of weeks and wore the hard orthotic. It did improve. I was scheduled not long after this for the Tybee Marathon in Georgia. Normally I don’t wear hard orthotics, but I did for this marathon. I have been pain free in my sinus tarsus for five years. I don’t need the hard orthotic now, I only used it for a couple of months to be sure I was going to get over the sinus tarsitis. Currently, with my two patients one is doing better with a new hard orthotic alone (a Sole Support offered through our office). The other patient has received one cortisone shot and has started using his hard orthotics and is also going through physical therapy. Only in severe and rare cases is the arthritis bad enough to require ankle surgery.