Interactive tool

TJA Complication Navigator

Findings to diagnoses to what CMS counts, for hip and knee replacement.

By Michael MacKechnie, MD, CM, FRCSC, FABOS, FAAOS. Reviewed September 2026; 2025 CMS THA/TKA Complication measure.
1 Case
Procedure
Where is the patient now
Exclusions from the cohort (open if any apply to the index encounter)
2 Find the diagnosis by category

Open a category, check what is present, select the diagnosis that is true. Chips say what CMS does with it.

What the chips mean
Counts as a complicationCMS records a complication on the diagnosis alone.Counts, only with a listed procedureCounted only if the same claim carries a listed procedure such as debridement, evacuation, or secondary closure; otherwise the diagnosis is recorded and nothing is counted.Not countedOutside the measure. Still must be the accurate diagnosis.

Claim conditions. On the index claim a complication is counted from a secondary diagnosis position when not present on admission. On a readmission, principal and secondary positions both count; myocardial infarction and pneumonia must additionally be present on admission of that readmission. Wound and surgical site bleeding diagnoses are counted only when a listed procedure code appears on the same claim. Mechanical, sepsis, pneumonia, pulmonary embolism, and myocardial infarction diagnoses are counted on the diagnosis alone. Death within 30 days is counted without a code.

3 Your selection and note
+ Comorbidities for risk adjustment
+ Pairs that split counted from not counted

The same bedside finding can be coded two ways, and CMS counts only one. Every one of the 442 diagnoses and 1,191 listed procedures in the 2025 CMS specification is built in; a few of the pairs that matter most (gold means it counts only with a listed procedure on the claim):

Why this matters (read once)
CMS counts specific diagnoses recorded within 7, 30, or 90 days of an elective primary hip or knee replacement as complications of that surgery, and publishes the rate. Two diagnoses that describe similar findings at the bedside can land on opposite sides of that list: superficial incisional infection T81.41XA counts, cellulitis of the leg does not. A nonspecific or default code can record a complication the patient never had, and an imprecise code can hide one they did. The right answer is always the diagnosis that is true, chosen with full awareness of what it does. Some diagnoses count only when the same claim also carries one of the measure's listed procedures (for wound infection and surgical site bleeding, a procedure such as debridement, evacuation, or secondary closure); an infection managed without a procedure records the correct diagnosis and generates no counted event.

Criteria sources. CDC/NHSN Patient Safety Component Manual, Surgical Site Infection Event; 2018 International Consensus Meeting definition of periprosthetic joint infection; Fourth Universal Definition of Myocardial Infarction (2018); Sepsis-3 (2016); ICD-10-CM Official Guidelines for Coding and Reporting. Measure status for each diagnosis was derived from the complete 2025 CMS code specification. Specifications are updated annually; institutional Vizient definitions may differ.

Education only. This tool does not constitute coding, billing, or legal advice and does not replace clinical judgment or the role of certified coding and clinical documentation professionals. Michael MacKechnie MD, CM, FRCSC, FABOS, FAAOS FABOS FAAOS.

Education only. This tool supports accurate, specific documentation. Final diagnosis selection must reflect the documented clinical condition. Michael MacKechnie, MD, CM, FRCSC, FABOS, FAAOS.

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