Question: Our orthopedist indicated that he performed a Repicci procedure and later told me that this is a unicondylar knee arthroplasty. Is there a code for this, and can we also code a diagnostic knee arthroscopy with it to confirm necessity? Indianapolis Subscriber Answer: This procedure refers to the product implanted, most likely a "Repicci II" unicondylar knee implant. Because it signifies a unicondylar knee arthroplasty, report 27446 (Arthroplasty, knee, condyle and plateau; medial OR lateral compartment). Your documentation should indicate which compartment (whether medial or lateral) the surgery affected. You cannot bill 29870 (Arthroscopy, knee, diagnostic, with or without synovial biopsy [separate procedure]) in addition to 27446. The arthroscopy is included in the arthroplasty and will therefore always be denied when billed together.