Podiatry Coding & Billing Alert

Follow these steps to understand TMT procedures.

When trauma occurs to a foot as it is in the process of pointing downward, the result is known as a Lisfranc injury. It results in swelling, bruising, and pain to the midfoot area, and if misdiagnosed, can lead to arch collapse and complex corrective surgery.

If your provider correctly diagnoses the condition in time, however, there are a number of less complex surgical options that can treat the condition effectively and prevent long-term problems. Here, we outline each one as we look at this typical Lisfranc case study.

The case: A 24-year-old patient reports to your podiatrist complaining of pain and swelling in the midfoot area of the left foot from an injury picked up while playing in a soccer game.

After an examination of the patient’s foot and a computerized tomography (CT) scan, your podiatrist diagnoses the patient with a Lisfranc dislocation of the left foot.

Step 1: Know Lisfranc Injuries

“When coding a Lisfranc injury it is important to understand the anatomy of the injured area. Ask yourself, ‘Where is the Lisfranc joint?’ It is where the metatarsal bones and the tarsal bones connect,” explains Jennifer McNamara CPC, CCS, CPMA, CRC, CGSC, COPC, AAPC Approved Instructor, director of education and coding at OncoSpark in Southpark, Texas.

The midfoot region contains the Lisfranc joint complex: a group of small bones joined by ligaments. Injuries to the area can range from low-energy strains and tears to the ligaments to high-energy bone dislocations and fractures, according to the American Academy of Orthopedic Surgeons (AAOS) (https://orthoinfo. aaos.org/en/diseases--conditions/lisfranc-midfoot-injury).

Step 2: Know Your ICD-10-CM Dx Coding Options

You can quickly and easily narrow down your ICD-10 code choices for Lisfranc injuries first by going straight to the Chapter 19: Injury, poisoning and certain other consequences of external causes (S00-T88) codes and, more specifically, the Injuries to the ankle and foot (S90-S99) section of the chapter.

Knowing that the injury codes are differentiated by anatomical region will then help you quickly narrow down the code choice even further to S93.- (Dislocation and sprain of joints and ligaments at ankle, foot and toe level). Anatomic knowledge will then get you to the appropriate 4th character, as knowing that a synonym for the Lisfranc joint is the tarsometatarsal (TMT) joint will help you land on S93.32- (Subluxation and dislocation of tarsometatarsal joint). You’ll add 7th characters 2 and A to the code to indicate this injury is to the patient’s left foot, and that the patient is undergoing active treatment for the injury.

For partial dislocations, you’ll still use S93.32-, as the code covers both full and partial (subluxation) dislocations.

For less severe Lisfranc injuries look to S93.62- (Sprain of tarsometatarsal ligament of foot).

Step 3: Know Your Treatment Coding Options

Clinically, a dislocation describes the displacement of two bones that become out of place at the joint that connects them. This means your provider will have to perform surgery on the patient’s midfoot, and that you will have to go deep into your podiatrists notes to determine the exact nature of the surgery. Fortunately, CPT^® only gives you four possibilities, and you can quickly narrow them down by knowing just a few clinical terms.

Open vs. closed: A fracture is called closed if there is no break in the skin and open if the bone fragment has broken the skin or there is a wound present along with the fracture. This allows you to choose from two codes immediately:

• 28600 (Closed treatment of tarsometatarsal joint dislocation; without anesthesia)
• 28615 (Open treatment of tarsometatarsal joint dislocation, includes internal fixation, when performed)

Clinical responsibility for 28600: Closed treatment indicates the podiatrist first reduced the TMT joint dislocation by manually pushing or pulling to bring the bones back to their normal alignment, a treatment also known as manipulation.

Coding alert 1: The code stipulates anesthesia was not used during the procedure. If the podiatrist’s notes indicate it was used, you’ll reach for 28605 (Closed treatment of tarsometatarsal joint dislocation; requiring anesthesia) instead.

Clinical responsibility for 28615: During this procedure, the podiatrist makes an incision in the skin over the dislocated joint. They then dissect down through the subcutaneous tissue, protecting the nerves and vessels. Next, they retract the muscles to have adequate exposure of the dislocated bones and adjust the bones to reduce the dislocation. They then fix the reduced joint with an implant and close the wound by suturing the skin layers together. Lastly, they place the foot in a splint or brace for a period of four weeks.

Coding alert 2: Look for the acronym ORIF in the provider’s notes. It stands for open reduction internal fixation, which is exactly what the CPT^® descriptor for 28615 states.

CPT^® also lists one other surgical procedure for Lisfranc dislocations: 28606 (Percutaneous skeletal fixation of tarsometatarsal joint dislocation, with manipulation).

Clinical responsibility for 28606: In this procedure, the provider begins with manipulation of the TMT dislocation in a manner similar to that described by 28600. Next, they create a small incision in the skin over the dislocated joint and insert pins and screws through this incision to hold the reduced dislocation in place, similar to the ORIF procedure described above. Finally, they close the wound by suturing the skin before placing the patient’s foot in a splint or brace for a period of four weeks.