Podiatry Coding & Billing Alert

Question: I have difficulty differentiating diagnosis of bunions from hallux valgus. Any tips?

Answer: First, a bunion is an enlargement of bone or tissue around the metatarsophalangeal (MTP) joint. A patient who always wears shoes that are too narrow around the toe box is prone to getting bunions.

Contrary to common misconception, bunion and hallux valgus are two different disorders. Although CPT lists bunion procedure codes, such as 28290 (Correction, hallux valgus [bunion], with or without sesamoidectomy; simple exostectomy [e.g., Silver type procedure]), as "hallux valgus corrections," physicians who perform these aren't necessarily correcting a hallux valgus.

Definition: If you look up 735.0 (Hallux valgus [acquired]), the definition reads, "Angled displacement of the great toe, causing it to ride over or under other toes." In fact, hallux valgus is simply a valgus deformity of the distal great toe (it points laterally) and doesn't have to overlap for orthopedist to call it hallux valgus.

Consequence: You shouldn't report 735.0 unless there is an angular deformity of the great toe. A person could suffer from a bunion, but not necessarily a hallux valgus.

A patient could have a bunion without his great toe overlapping upon the second toe. In this case, you would report 727.1 (Other disorders of synovium, tendon, and bursa; bunion), which is ICD-9 defines as "enlarged first metatarsal head due to inflamed bursa; results in laterally displaced great toe."

Warning: Some coders have used 736.70 (Unspecified deformity of ankle and foot, acquired) to specify a bunion without hallux valgus, but this is incorrect. Because a more specific code is available (727.1), use that instead.

Since many physicians use hallux valgus to refer to bunions in their op notes, it's best to check with your payers to see whether this minor discrepancy makes a difference.