Orthopedic Coding Alert

Examine and learn how to report real-world examples.

Rheumatoid arthritis is a chronic autoimmune disease that causes the immune system to attack the body’s own tissues. Rheumatoid arthritis, often referred to as RA, causes inflammation, pain, and swelling primarily in the joints, which can result in joint damage and stiffness. While rheumatoid arthritis may affect any joint, we will focus on the hand and wrist joints, which are commonly affected by the disease, causing deformity and loss of function.

Read on to learn about rheumatoid arthritis, the diagnosis codes, and how to report surgical procedures.

Understand ICD-10-CM Coding for Rheumatoid Arthritis

Assigning ICD-10-CM codes for rheumatoid arthritis depends on the type, rheumatoid factor status, affected joints, age of patient (adult vs. juvenile), and systemic involvement.

Adult rheumatoid arthritis codes depend on the rheumatoid factor status of the patient. Seropositive rheumatoid arthritis is arthritis that is rheumatoid factor-positive.

Coding examples of rheumatoid arthritis with a positive rheumatoid factor include:

• M05.9 (Rheumatoid arthritis with rheumatoid factor, unspecified)
• M05.79 (Rheumatoid arthritis with rheumatoid factor of multiple sites without organ or systems involvement)
• M05.60 (Rheumatoid arthritis of unspecified site with involvement of other organs and systems)

Arthritis that is rheumatoid factor-negative is also known as seronegative rheumatoid arthritis.

Examples of codes for RA with a negative rheumatoid factor include:

• M06.00 (Rheumatoid arthritis without rheumatoid factor, unspecified site)
• M06.09 (Rheumatoid arthritis without rheumatoid factor, multiple sites)
• M06.9 (Rheumatoid arthritis, unspecified)

Codes for juvenile idiopathic arthritis (JIA) are found in the M08.- (Juvenile arthritis) series. These codes include:

• M08.00 (Unspecified juvenile rheumatoid arthritis of unspecified site)
• M08.20 (Juvenile rheumatoid arthritis with systemic onset, unspecified site)
• M08.439 (Pauciarticular juvenile rheumatoid arthritis, unspecified wrist)

Know How to Select the Right Code

You will need to answer the following questions to choose the most accurate code:

1. Is the rheumatoid factor status documented? Determine whether the lab results show the patient is seropositive (RF-positive) or seronegative (RF-negative).
2. Does the disease affect a specific joint? The ICD-10-CM coding system includes codes that identify the affected joint(s) and laterality.
3. Are other organs or systems involved? Your code selection will also change if the patient has extra-articular manifestations affecting other body systems.

Code it: Rheumatoid arthritis of the left hand without rheumatoid factor. Report M06.042 (Rheumatoid arthritis without rheumatoid factor, left hand).

Code it: Rheumatoid nodule of the right hand. Report M06.341 (Rheumatoid nodule, right hand).

Lack of specificity in the documentation hampers code assignment, with orthopedic surgeons often stating that a patient has rheumatoid arthritis without providing additional details. For a diagnosis of “rheumatoid arthritis” without further detail, the ICD-10-CM default code M06.9 must be assigned.

Additional codes may also be assigned for deformity associated with rheumatoid arthritis, such as swan neck deformity, boutonniere deformity, and ulnar drift of the wrist.

Rheumatoid bursitis (M06.2- [Rheumatoid bursitis]) and nodules (M06.3- [Rheumatoid nodule]) are other related conditions your orthopedic hand surgeon may treat.

Examine CPT^® Coding for Rheumatoid Arthritis Surgery

Commonly performed orthopedic procedures for rheumatoid arthritis include joint replacement, joint fusion, synovectomy to remove inflamed joint linings, excision of nodules, and soft tissue procedures like tendon repair, transfer, realignment, and tenodesis.

CPT^® codes for these commonly performed procedures include:

• Arthroplasty: The provider repairs or replaces the damaged joint with prosthetic components. When performed on the finger joints, look to 26530-26536.

• Arthrodesis (joint fusion): A surgeon fuses bones together to create a stable, pain-free joint by eliminating movement. When performed on the hand or wrist, look to 26820-+26863 and 25800-25830.

• Synovectomy: The physician removes the inflamed synovial membrane (synovium) from the joint to relieve pain and prevent further damage. Synovectomy of the hand and wrist codes include 25115-25119 and 26130-26145.

• Osteotomy/resection: These procedures involve cutting (osteotomy) or removing part of a bone (resection) to correct deformities or reduce pressure. Examples include 25350-25365.

• Soft tissue procedures: These procedures address damage to ligaments and tendons, including:
  • Tendon repair
  • Tendon transfer, release, or realignment
  • Joint release
  • Nodule excision
  • Deformity correction

These procedures may be performed alone or in combination. When multiple procedures are performed, it is important to review CPT^® and Medicare National Correct Coding Initiative (NCCI) guidelines and edits to determine if the codes may be reported together. Careful use of modifiers will prevent inappropriate claim denials for procedures performed on different fingers.

Code it: Arthrodesis of the left wrist with autograft and synovectomy of the wrist joint. Report 25810 (Arthrodesis, wrist; with iliac or other autograft (includes obtaining graft)) appended with modifier LT (Left side). No additional code is reported for the synovectomy because 25105 (Arthrotomy, wrist joint; with synovectomy) is inclusive to 25810.

Code it: Silastic replacement arthroplasty of the right index finger proximal interphalangeal (PIP) and metacarpophalangeal (MCP) joints and right middle and ring finger PIP joints. Report  26356 (Repair or advancement, flexor tendon, in zone 2 digital flexor tendon sheath (eg, no man's land); primary, without free graft, each tendon) appended with F6 (Right hand, second digit), 26356 appended with F7 (Right hand, third digit), 26536 appended with F8 (Right hand, fourth digit), and 26531 (Arthroplasty, metacarpophalangeal joint; with prosthetic implant, each joint) appended with F6.

Heidi Stout, CPC, COSC, President, Coder on Call, Inc.