Complete Coding for Iatrogenic Injuries

Complete Coding for Iatrogenic Injuries

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By Cari Greenwood, RHIA, CCS, CPC

Aisha is a 71-year-old-female patient with osteoarthritis of the left hip. She sees Dr. McCarthy who performs a left total hip replacement. During the procedure Aisha suffers a minor fracture of the shaft of the femur secondary to insertion of the prosthesis. Dr. McCarthy places a percutaneous pin through the fracture site to hold it in place while it heals. The coding professional assigned to code Aisha’s procedure knows the fracture is an intraoperative complication of the procedure, but he is unsure how to report it. Does this scenario sound familiar?

One situation that many health information management (HIM) professionals who assign diagnosis codes find difficult is determining the appropriate code(s) to assign for intraoperative or postprocedural complications. Once they’ve cleared the hurdle of verifying that the condition is indeed a complication of the care provided, locating the correct code(s) to report the complication can still be daunting.

Although most code selections today are made with the aid of encoders, when trying to find a code for a complex diagnosis, if you’re not sure how to proceed, incorrect choices in the encoder can lead you down the wrong path. In these cases, you can’t beat going back to the basics of identifying pertinent guidelines, searching the Alphabetic Index and verification in the Tabular List.

ICD-10-CM Chapter 19 Coding Guidelines

To provide assistance in proper code selection, the 2020 updates to the ICD-10-CM Official Guidelines for Coding and Reporting introduced a new guideline for ICD-10-CM Chapter 19: Injury, Poisoning, and Certain Other Consequences of External Causes. This addition to the guidelines clarifies both what codes not to assign for intra- and postoperative complications as well as what type of codes should be assigned.

New guideline I.C.19.b.3 states, “Injury codes from Chapter 19 should not be assigned for injuries that occur during, or as a result of, a medical intervention. Assign the appropriate complication code(s).”

Coding professionals are familiar with using codes from Chapter 19 to report injuries such as fractures, lacerations, hematomas, burns, or poisonings, and when a coding professional sees a diagnosis of “fracture” their first reaction typically is to locate an “S” code to report this kind of injury. However, the new guideline clarifies that this is not the correct coding action if the fracture occurred intraoperatively—such as the fracture from the example at the beginning of this article, which represents an iatrogenic injury because it occurred as the result of a medical intervention (the total hip replacement). The guideline steers the coding professional away from Chapter 19 codes when injuries such as these occur as the result of a procedure and points them to the complication codes for an appropriate option to report the injury. Unfortunately, locating the correct complication code(s) is often where the process gets difficult.

Fortunately, digging deeper into the Chapter 19 guidelines reveals additional guidance related to the assignment of complication of care codes for intra- and postoperative complications. Guideline I.C.19.g.5 states, “Intraoperative and postprocedural complication codes are found within the body system chapters with codes specific to the organs and structures of that body system. These codes should be sequenced first, followed by a code(s) for the specific complication, if applicable. Complication codes from the body system chapters should be assigned for intraoperative and postprocedural complications (e.g., the appropriate complication code from chapter 9 would be assigned for a vascular intraoperative or postprocedural complication) unless the complication is specifically indexed to a T code in chapter 19.”

The direction in this guideline indicates, with a few exceptions, that codes for intra- and postoperative complications will come from the ICD-10-CM chapter of codes for the body system to which the structure or organ that was injured, intra- or postoperatively, belongs. Based on the direction in this guideline, the complication code to report the intraoperative fracture of the femur from the example should come from Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue.

With the applicable guidelines identified and reviewed, the next step is to consult the Alphabetic Index.

Searching the Alphabetic Index and Tabular List

Armed with the direction in the guidelines, it’s expected that a valid search of the ICD-10-CM Alphabetic Index will ultimately lead to a reference for a code from Chapter 13. Because it’s known that the correct code is a complication code, not an injury code, it seems logical to begin a search of the index with the main term “complication.”

However, in this case, what seems most logical is in fact not the most direct search option for determining an appropriate code. Beginning with the main term “complication” takes the coding professional through a convoluted search of the index that requires following many instructional notes and leads to several dead ends. The correct code is easily found by searching under the main term for the condition “fracture, traumatic” and the subterms “following insertion (intraoperative) (postoperative) of orthopedic implant, joint prosthesis or bone plate” and “femur.” This index entry directs the assignment of code M96.66-, which is a code from the musculoskeletal body system chapter of ICD-10-CM. The dash at the end of the code in the index means an additional character(s) is needed to complete the code. That character(s) will be identified in the final step of code assignment, verification of the code in the Tabular List.

Consulting the Tabular List shows that codes from subcategory M96.66 require a sixth character to specify laterality of the injury and that “2” is the character specifying a fracture of the left leg. The final code for intraoperative fracture of the femur secondary to total hip replacement is M96.662, Fracture of femur following insertion of orthopedic implant, joint prosthesis or bone plate, left leg.

Sequencing Complication Codes

Referring back to guideline I.C.19.g.5 reveals additional guidance indicating that body system–specific complication codes should be sequenced first and followed by codes for the specific complications, if applicable. In the case of the example presented, this part of the guideline is irrelevant and no additional codes are needed. A code for the specific complication (femur fracture) is not necessary because the fracture is already identified in the body system complication code. Additionally, this was the operative episode, which means the principal diagnosis will be osteoarthritis and all codes assigned for complications will be reported as secondary diagnoses.

External Cause Status

When an injury occurs, it’s common coding practice to assign an external cause code from Chapter 20 of ICD-10-CM. Even so, exceptions always exist and as indicated by guideline I.C.20.a.8, an external cause code should not be assigned in cases where the external cause is included in the code from another ICD-10-CM chapter. The description of code M96.662 not only indicates that the nature of the complication is a fracture, it confirms the cause of the fracture as the implantation of the joint prosthesis. As such, it is not appropriate to assign an additional code to identify the external cause of this injury.

After considering the direction in the guidelines, Alphabetic Index and Tabular List, it’s been determined that the coder from the example at the beginning of this article should assign a single code M96.662 to report Aisha’s intraoperative femur fracture. This example illustrates that when trying to find the right code for an intra- or postoperative complication, being persistent and taking the time to use basic coding references will eventually pay off in helping the coder identify the correct codes, the appropriate number of codes to report, and how those codes should be sequenced.


Centers for Medicare and Medicaid Services. ICD-10-CM Official Guidelines for Coding and Reporting, 2020.

Cari Greenwood is an independent coding educator.

Continuing Education Quiz

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  • Quiz ID: Q2049108
  • Expiration Date: August 1, 2021
  • HIM Domain Area: Revenue Cycle Management