Podiatry Coding & Billing Alert

Question: The patient, a professional soccer player, was born with an os trigonum bone in his left foot. The patient has been experiencing swelling, tenderness, and limitation of motion. My podiatrist diagnosed him with os trigonum syndrome. My 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 surgical management to excise 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?

California Subscriber

Answer: You should report 28120 (Partial excision (craterization, saucerization, sequestrectomy, or diaphysectomy) bone (eg, osteomyelitis or bossing); talus or calcaneus)) as the CPT^® code on your claim. You would report Q68.8 (Other specified congenital musculoskeletal deformities) as the ICD-10-CM 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 varies in size, and it is attached to the posterior aspect of the talus by a fibrous band of tissue. Only a small number of patients have this congenital condition. 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: Since conservative measures failed and the patient still experienced swelling, tenderness, limitation of motion and weakness, your podiatrist performed surgical management to excise the os trigonum.

The primary goal of operative treatment for posterior ankle impingement is excision of the impeding anatomical structure. In this procedure, the podiatrist removes the fractured os trigonal or posterolateral talar process in its entirety. The podiatrist makes an incision behind the patient’s ankle, identifies the os trigonum, and dissects it free of its surrounding soft-tissue attachment.