Boot 250.00 for Charcot Foot, Embrace Dual Dxs

Internal Medicine Coding Alert 2009

In your next education session, encourage internists to specify underlying cause.

Stop equating 250.00 with "Charcot foot," and realize your ICD-9 code repertoire might instead involve another cause.

Problem: An elderly patient presents with what your internist diagnoses as "Charcot foot," and requires treatment. You know the main cause of this condition is uncontrolled type 2 diabetes mellitus (DM). So you should code 250.00 (Diabetes mellitus) for the diagnosis, right? Not so fast. There's more than meets the eye — or foot — when it comes to correctly coding this condition.

Expand Charcot's Culprit Beyond Diabetes

Despite an improvement in the understanding of the cause and development of diabetic foot problems in the last two decades, the current epidemic of type 2 diabetes ensures that the incidence of foot problems will continue to increase in the diabetic population, says Andrew Boulton, MD, in a 2008 issue of the journal Foot and Ankle Surgery. One such problem is Charcot foot — also known as Charcot's joint or neuropathic arthropathy — which occurs when a joint deteriorates because of nerve damage, a common complication of diabetes. Charcot's joint primarily affects the feet, hence the term "Charcot foot".

Catch: "While diabetes is the most common cause [of Charcot arthropathy], there are others," says Bruce Rappoport, MD, CPC, CHCC, medical director of Broward Health's Best Choice Plus and Total Claims Administration in Fort Lauderdale, Fla. Therefore, 250.00 should not be an automatic coding choice.

Any condition that causes sensory or autonomic neuropathy can lead to a Charcot joint, according to Mrugeshkumar Shah, MD, MPH, at Massachusetts General Hospital/Spaulding Rehabilitation Hospital. Charcot arthropathy occurs as a complication of not only diabetes but also:

• 094.x — Neurosyphilis.
• 303.9 — Chronic alcoholism.
• 030.x — Leprosy.
• 741.9 — Meningomyelocele (Spina bifida).
• 336.0 — Syringomyelia.

Other possibilities include congenital insensitivity to pain, spinal cord injury, and renal dialysis, Shah reported.

Go With 713.5 as Secondary Diagnosis

So how do you get the correct Charcot foot diagnosis? Let's work from the bottom up.

For the Charcot foot disorder, you'll use 713.5 (Arthropathy associated with neurological disorders).

Both Charcot's arthropathy associated with diseases classifiable elsewhere and neuropathic arthritis associated with diseases classifiable elsewhere fall under 713.5, according to the brackets following the code's description.

Coach Your Physician to Specify Underlying Cause

Before listing neuropathic joint disease [Charcot's joints] as 713.5, make sure to first list the underlying disease. Under 713.5, ICD-9 includes these possibilities:

• NOS (094.0).
• Diabetic (249.6, 250.6).
• Syringomyelic (336.0).
• Tabetic [syphilitic] (094.0).

Ask your provider to document the etiology. "I would hate to label a patient with a diagnosis like neuorsyphilis if he or she does not have it," Rappoport says.

If the diagnosis is in fact Charcot foot due to diabetes, then code 250.6x (Diabetes with neurological manifestations) after 713.5. "When in doubt, ask the provider to document," Rappoport stresses.