The ICD-10-CM code set provides the opportunity for the coder to paint the clinical picture of a patient’s injuries/conditions in greater depth and with more clarity than the coding in ICD-9. An important way ICD-10 is different from ICD-9 is the addition of the convention to indicate laterality. This convention allows for the capture of increased complexity of information by the ICD-10 code set. This increased complexity equates to better information for research surrounding injury prevention and best practices in injury treatment.
ICD-10 codes have specific characters that indicate whether an injury affects the patient’s right or left side. For example:
- ICD-10-CM: Displaced fracture of the body of the right calcaneus – S92.011 vs. Displaced fracture of the body of the left calcaneus – S92.012
- ICD-9-CM: Displaced fracture of the body of the right calcaneus – 825.0 vs. Displaced fracture of the body of the left calcaneus – 825.0
In the case of ICD-10 the 6th character of the code indicates which side of the body was affected by the fracture whereas in ICD-9 the code is the same whether the injury affects the patient’s right or left foot.
The indication of laterality in the diagnosis coding provides a convenient cross reference when analyzing whether the diagnostic codes assigned support the medical necessity of procedures performed. When reporting procedures, outpatient coders would be wise to take care to make sure the body site modifiers assigned to CPT codes match the laterality indicated by the assigned diagnosis code.
In some cases characters representing conditions affecting the patient bilaterally are available. For example:
- ICD-10-CM: Osteoarthritis of right and left knee, secondary to bilateral dislocations from a skiing accident – M17.2 vs. Osteoarthritis of right knee secondary to dislocation from a skiing accident – M17.11 or Osteoarthritis of left knee secondary to dislocation from a skiing accident – M17.12
- ICD-9-CM: Osteoarthritis of the right and left knee secondary to bilateral dislocations from a skiing accident – 716.16
In the case of the ICD-10 codes the 4th character of “2” indicates a bilateral condition versus a 4th character of “1” which indicates a unilateral condition (note that the 5th character of the unilateral code differentiates between the right and left knee). In comparison, the 5th digit of the ICD-9 code indicates the affected site as “lower leg” and provides no indication of laterality. Additionally, in ICD-9 the code 716.16 would be reported only once even if the patient had the condition in both knees. The addition of codes that report bilateral sites being affected by the same condition helps improves the ability of the coding to capture the true measure of the severity of the patient’s condition.
Visit AAPC’s Healthcare Business Monthly’s May issue to get more details about how the conventions used in ICD-10 will change and improve the data that comes from the coding of orthopedic injuries. Looking to get more of your ICD-10 questions answered? Refer to our ICD-10 FAQ section.