The primary surgical procedure is a total knee arthroplasty, which is an open procedure. The correct anesthesia code is 01402 (Anesthesia for open procedures on knee joint; including total knee arthroplasty). The femoral nerve block was performed by the anesthesiologist in the recovery room specifically for postoperative pain management, not as the primary anesthetic for the surgery. Therefore, it is a separately reportable service. CPT® code 64447 represents the single injection femoral nerve block. Modifier 59 is appended to signify a distinct procedural service from the primary anesthesia. Modifier LT is used to indicate the procedure was performed on the left side.

A. 01404 is for knee amputation anesthesia, not arthroplasty. 64450 is a non-specific nerve block code, and 01996 is for daily management of a continuous infusion.

B. 01380 is the anesthesia code for a closed knee procedure; a total knee arthroplasty is an open procedure.

D. 64448 describes a continuous infusion via catheter, which is not documented in the scenario. 01996 is also inappropriate.

1. American Medical Association (AMA). (2023). CPT® 2024 Professional Edition.

Page 91: Code 01402 is listed as "Anesthesia for open procedures on knee joint; including total knee arthroplasty."

Page 518: Code 64447 is listed as "Injection

anesthetic agent(s) and/or steroid; femoral nerve

single."

Appendix A

Modifiers: Modifier 59

Distinct Procedural Service

is defined as appropriate to identify procedures/services that are not normally reported together but are appropriate under the circumstances. This includes a separate procedure for postoperative pain management after a surgical session.

2. American Society of Anesthesiologists (ASA). (2023). Relative Value Guide®.

Anesthesia for Surgical

Medical and Diagnostic Procedures Section: The guide clarifies that the administration of nerve blocks for postoperative pain management is a separate service from the anesthetic care for the primary procedure and is not included in the base units of the anesthesia code. This supports the separate reporting of code 64447.

3. AAPC. (2023). 2024 CPC® Study Guide.

Chapter 13

Anesthesia: The guide explains that when an anesthesiologist performs a block for postoperative pain management

it is coded separately from the anesthesia for the surgery itself

often requiring modifier 59 to bypass bundling edits. It specifically contrasts this with a block used as the primary surgical anesthetic

which would be bundled.