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April 9, 2012

Coding for Open Wounds
For The Record
Vol. 24 No. 7 P. 28

An open wound is an injury that causes a break in the skin or mucous membrane. In ICD-9-CM, open wounds are classified to categories 870 to 897. Common types include the following:

• Abrasion: caused by rubbing or scraping the skin against a rough or hard surface. Typically, the wound is superficial, and the bleeding is limited.

• Incision: a cut caused by a sharp instrument such as a knife or razor blade. This type of wound may be deep, involving muscles, tendons, and nerves, with the potential for heavy bleeding.

• Laceration: caused by a jagged, irregular, or blunt edge resulting in tearing of soft tissues. Bleeding may be heavy, and the wound may be deep.

• Puncture: a piercing wound that causes a small hole in the tissues. Although the external wound is minor, there may be a more serious internal injury.

• Avulsion: a forcible tearing or partial tearing away of tissues typically caused by gunshot wounds, explosions, and animal bites.

In ICD-9-CM, a traumatic amputation is considered an open wound classified to categories 870 to 897. However, it excludes open wounds associated with burn (940.0 to 949.5); crushing (925 to 929.9); puncture of internal organs (860.0 to 869.1); superficial injury (910.0 to 919.9); and those incidental to dislocation (830.0 to 839.9), fracture (800.0 to 829.1), internal injury (860.0 to 869.1), and intracranial injury (851.0 to 854.1).

The fourth-digit subcategory may identify whether the wound is complicated. A complicated open wound includes mention of delayed healing, delayed treatment, foreign body retention, or infection. There is no strict definition of delayed healing or treatment. If a patient delays seeking treatment by one week, for example, and the wound does not seem to be healing appropriately, then the complicated code should be used. If the coder is unsure, query the physician. The delayed treatment and healing tends to lead to infections, which then qualifies as a complicated open wound.

Internal injury of the thorax, abdomen, and pelvis is classified to categories 860 to 869. Injuries to internal organs include those from blasts, blunt trauma, bruising, concussion (except cerebral), crushing, hematoma, laceration, puncture, tear, and traumatic rupture.

The coding directive before category 860 states, “The description ‘with open wound,’ used in the fourth-digit subdivisions, includes those with mention of infection or foreign body.”

When multiple injuries occur, a separate ICD-9-CM code should be assigned for each injury whenever possible, though ICD-9-CM may direct the coder to assign a combination code. For example, a patient was admitted with a fracture of the proximal end of the tibia and fibula. ICD-9-CM directs the coder to use code 823.02 to identify both fractures.

The coder should be as specific as possible and should avoid using the nonspecific multiple injury code to identify injuries of multiple sites. A code for multiple injuries may be used when there is insufficient data available in the medical record. For example, if a patient is admitted with contusions of the back, forearm, face, and abdomen, then a separate code should be assigned for each documented site. However, if the patient is admitted with multiple contusions of the trunk with no further information of affected sites documented, then multiple contusions of the trunk (922.8) may be assigned.

It should be noted that superficial injuries such as abrasions are not coded when associated with more severe injuries of the same site.

According to the ICD-9 official guidelines, when multiple injuries exist, the code for the most severe injury, as determined by the physician, and the treatment provided is sequenced as the principal diagnosis.

When there is a break in the skin, an infection may occur. One type is cellulitis, which involves the inflammation of tissues under the skin. The affected area becomes swollen, red, tender, and warm to the touch. Cellulitis is classified to categories 681 and 682. The specific code assignment will depend on the site of the cellulitis.

Sequencing of cellulitis vs. open wound as principal diagnosis depends on the circumstances of admission. If the focus of the admission is on the cellulitis, with the open wound being minor or previously treated, then the cellulitis should be sequenced as the principal diagnosis with the complicated open wound coded as a secondary diagnosis. If, however, the open wound is the primary focus of treatment, then the opposite would be true. (AHA Coding Clinic for ICD-9-CM, 1991, second quarter, pages 5-7).

Coding and sequencing for open wounds 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. 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.


ICD-10-CM Coding for Open Wounds
Injuries have been arranged into the following blocks (category code ranges) in ICD-10-CM:

• head (S00 to S09);

• neck (S10 to S19);

• thorax (S20 to S29);

• abdomen, lower back, lumbar spine, pelvis, and external genitals (S30 to S39);

• shoulder and upper arm (S40 to S49);

• elbow and forearm (S50 to S59);

• wrist and hand (S60 to S69);

• hip and thigh (S70 to S79);

• knee and lower leg (S80 to S89);

• ankle and foot (S90 to S99);

• unspecified multiple injuries (T07); and

• unspecified body region (T14).

ICD-9-CM classifies injuries first by type and then by anatomical location, which groups together injuries of one type for all body sites. For example, a crush injury of the ankle is located under “Crushing Injury” (925 to 929). The code for a crushed ankle (928.21) is located within this section.

In ICD-10-CM, injuries are first classified by specific anatomical site/body part and then by type of injury, which in essence groups together all injuries for a particular body site. A crush injury of the ankle is located under “Injuries to the Ankle and Foot” (S90 to S99). The category code for a crushed ankle (S97-) is located within this section.

There are consistent injury types classified in all the body regions as well as injuries unique to a body region. An example of consistent injury types is that there is a category code for superficial injuries in each body site in the range of S00 to S99. On the other hand, traumatic brain injuries are unique to section S00 to S09, Injuries to the head.

Codes for open wounds are also found consistently across the body sites. The types of open wounds classified in ICD-10-CM are laceration without foreign body, laceration with foreign body, puncture wound without foreign body, puncture wound with foreign body, open bite, and unspecified open wound.

In ICD-9-CM, open wounds are classified as complicated or not. In ICD-10-CM, separate codes are provided for lacerations and puncture wounds with and without a foreign body. Furthermore, there is an instructional note associated with the category codes directing the coder: “Code also any associated wound infection.” The concept of delayed treatment and healing has been removed from the ICD-10-CM classification. In ICD-10-CM, open wounds, depending on the anatomical site, may have additional and/or unique code specificity associated with them. A few examples include with or without penetration into a body cavity or organ; further classification of the laceration as minor, moderate, or major; and further anatomic specification such as left/right, front/back, flexor/extensor.

Typically, a seventh character, which indicates the encounter (such as initial or subsequent), is required. Late effects of injuries are also classified to the specific injury with a seventh character of sequela.

— AH