Next week I am having arthroscopic surgery to remove a tiny bone caught between the lower leg bone and the heel bone. I expect to have a full and easy recovery. But I would like to know more about other patients’ experiences. Does anyone “fail” with this kind of operation? What happens then?

It sounds like you may have an os trigonum. This bone is located on the talus, which is part of the ankle. When the foot and ankle are plantarflexed (toes pointed downward), the os trigonum (and soft tissues attached to it) get pinched between the tibia (lower leg bone) and the calcaneus (heel bone).

Ankle pain can develop that is so severe, the athlete must stop all activities and motions that aggravate the problem. Running and jumping are out of the question until the inflammation has subsided. Physical therapy may be needed to address postural and alignment issues that could be contributing.

If conservative (nonoperative) care is not successful in treating the problem, then surgery to remove the bone may be needed. Minimally invasive procedures are available now to take care of this problem. The surgeon uses a small, thin scope (either an arthroscope or an endoscope) with a tiny TV camera on the end to enter the joint and see what’s going on.

The surgeon then excises (takes out or removes) the os trigonum. Most patients improve significantly and are pleased with the results. The technique is considered “safe and effective.”

The choice between surgical instruments and techniques used (arthroscope versus endoscope) may depend on the level of surgeon experience and expertise. Large os trigonums are more difficult to remove using the arthroscopic approach. There is very little room inside the subtalar joint where the scope enters. It’s also difficult to see inside this area. Using the endoscopic approach from the back side of the ankle requires cutting the flexor hallucis longus tendon but gives the surgeon more room to work in and greater visibility.

Open surgery may be needed if arthroscopic and/or endoscopic techniques are not successful in eliminating the problem. But this happens very infrequently when it is a simple os trigonum exicision. Studies show that more serious complications occur when complex surgery is required (e.g., os trigonum excision AND ankle fusion).