Podiatry Coding & Billing Alert

Question: The patient, a professional volleyball player, was born with an os trigonum bone in their left foot. The patient has been experiencing swelling, tenderness, and limitation of motion. My podiatrist diagnosed them with os trigonum syndrome. The podiatrist first recommended conservative treatment including anti-inflammatory medication, activity modification, and immobilization for the pain. However, the patient’s pain continued for months, so my podiatrist recommended surgery to remove the os trigonum. During this procedure, my podiatrist made an incision behind the patient’s ankle, identified the os trigonum, and dissected it free of the surrounding soft-tissue attachment. What codes should I report on this claim?

Vermont Subscriber

Answer: You should report 28120 (Partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) bone (eg, osteomyelitis or bossing); talus or calcaneus)) for the procedure code on your claim. You would also report Q68.8 (Other specified congenital musculoskeletal deformities) as the ICD-10-CM diagnosis code on your claim.

Os trigonum defined: The os trigonum is an extra (accessory) bone that lies behind the ankle joint that exists when one area of bone does not fuse with the rest of the talus (ankle bone) during growth. The os trigonum’s size can differ, and it’s connected to the back part of the talus via a band of fibrous tissue. This congenital condition is present in only a limited number of individuals. The bone can become painful after trauma to the back of the heel, after an ankle sprain, or due to Achilles tendinitis.

Patients who frequently assume plantarflexion (foot pointed downward) positions may experience posterior impingement from the os trigonum. Typical patients with os trigonum include athletes such as ballet dancers, soccer players, runners, and volleyball players.

Code 28120 explained: Because noninvasive treatments were unsuccessful and the patient continued to suffer from inflammation, sensitivity, restricted movement, and lack of strength, your foot specialist carried out a surgical procedure to remove the os trigonum.

The primary goal of surgical intervention for posterior ankle impingement is to remove the obstructing anatomical part. During this operation, the foot specialist entirely eliminates the broken os trigonum or posterior-lateral talar process. The specialist creates a cut at the back of the patient’s ankle, locates the os trigonum, and carefully separates it from the surrounding soft tissue it’s attached to.