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February 19, 2007

Coding for Osteoarthritis
For The Record
Vol. 19 No. 4 P. 38

Osteoarthritis is a chronic joint disorder characterized by degeneration of joint cartilage and the adjacent bone. Degeneration occurs due to rubbing of the joint surfaces, causing a wearing away of the tissues. It is the most common type of arthritis and usually occurs in the hands, knees, hips, and spine.

Other common names for osteoarthritis are degenerative arthritis, hypertrophic arthritis, degenerative joint disease, and osteoarthrosis. Osteoarthritis of most sites, except the spine, is assigned to ICD-9-CM category 715. Osteoarthritis of the spine is assigned to category 721. The specific code assignment depends on the site of the spine involved (ie, cervical, thoracic, lumbar) and if myelopathy is present. In category 715, the fifth-digit code assignment identifies the specific site involved. The fourth-digit code assignment identifies whether the osteoarthritis is generalized or localized.

Generalized osteoarthritis (code 715.0x or 715.8x) affects many joints, while localized osteoarthritis affects the joints of one site. Localized osteoarthritis can be further broken down into two other categories: primary and secondary. Primary osteoarthritis (715.1x), also known as idiopathic, affects joints of one site with no known cause. Secondary osteoarthritis (715.2x) affects a joint of one site and is due to some external or internal injury or disease. If the localized osteoarthritis is not specified as primary or secondary, code 715.3x is assigned. Bilateral involvement of the same site is still considered localized and is included in the fifth digit for the site. Code 715.9x is assigned when it is not specified as generalized or localized.

However, it is encouraged not to assign this unspecified code. According to AHA Coding Clinic for ICD-9-CM, when the osteoarthritis “affects only one site but is not identified as primary or secondary, it is coded to 715.3x.” In addition, AHA Coding Clinic for ICD-9-CM goes on to say that “if it involves more than one site but is not specified as generalized, assign code 715.8x” (AHA Coding Clinic for ICD-9-CM, 1995, second quarter, page 5).

The symptoms of osteoarthritis include the following:

• joint pain, which also includes pain of the muscles, ligaments, synovial capsule, and bones around the joint;

• joint stiffness;

• loss in range of motion of affected joints;

• discomfort in joint before or during a change in weather;

• joint swelling; and

• bony lumps in joints of fingers (nodes).

Osteoarthritis is typically diagnosed based on findings in a physical exam, which includes the description of the symptoms and location and pattern of pain. An x-ray will confirm the diagnosis. Blood tests, computed tomography scans, and MRIs are not used to diagnosis osteoarthritis but may be performed to rule out other types of arthritis. A joint aspiration may also be done to rule out other diseases.

Although there is no known cure for osteoarthritis, the goals of treatment include the following:

• relieving pain;

• protecting joints; and

• enhancing joint function.

Medications do not reverse or slow the progression of joint damage, but they do relieve pain, reduce inflammation, and improve stiffness. The following prescription and over-the-counter medications are typically used in the treatment of osteoarthritis:

• pain relievers — acetaminophen (Tylenol), tramadol (Ultram);

• non-steroidal anti-inflammatory drugs, which reduce inflammation, joint pain, and stiffness — ibuprofen (Advil, Motrin IB), naproxen sodium (Aleve), ketoprofen (Orudis), diclofenac (Cataflam, Voltaren), nabumetone (Relafen);

• COX-2 inhibitors, which reduce pain and inflammation — Celecoxib (Celebrex);

• topical pain relievers, which can provide temporary arthritis relief — trolamine salicylate (Aspercreme, Sportscreme), methyl salicylate, menthol, and camphor (Icy Hot, Ben-Gay), capsaicin.

• antidepressants, which reduce chronic pain and help depression and insomnia — amitriptyline (Elavil), nortriptyline (Pamelor, Aventyl); and

• injection of pain relievers, which also reduce inflammation —corticosteroid, hyaluronic acid (viscosupplementation).

If the joint can no longer function properly, the patient may require surgery to replace it. Total hip replacement is classified to code 81.51, and partial hip replacement goes to code 81.52. Code 81.54 identifies both partial and total knee replacement. Revision of a joint will go to a different range of codes. According to AHA Coding Clinic for ICD-9-CM, “Any time the joint is replaced or revised after the initial replacement would be considered a revision” (AHA Coding Clinic for ICD-9-CM, second quarter 1996, page 13). The codes for the hip replacement components include the following:

• 00.70, Revision of hip replacement, both acetabular and femoral components;

• 00.71, Revision of hip replacement, acetabular component;

• 00.72, Revision of hip replacement, femoral component; and

• 00.73, Revision of hip replacement, acetabular liner and/or femoral head only.

The codes for the knee replacement components include the following:

• 00.80, Revision of knee replacement, total (all components);

• 00.81, Revision of knee replacement, tibial component;

• 00.82, Revision of knee replacement, femoral component;

• 00.83, Revision of knee replacement, patellar component; and

• 00.84, Revision of total knee replacement, tibial insert (liner).

There is an instructional note under subcategory 00.8 that states, “Report up to two components using 00.81-00.83 to describe revision of knee replacements. If all three components are revised, report 00.80.” In other words, if the tibial and femoral components are revised, assign both code 00.81 and code 00.82.

Coding and sequencing for osteoarthritis are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to nearly 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.