R418 – Synovectomy/debridement - wrist
OHIP Radiology Code — MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES · Schedule of Benefits
Synovectomy/debridement of the wrist. This is a surgical procedure for the removal of the synovial membrane and/or debridement of tissue from the wrist. The fee for the surgeon is a flat rate. Fees for assistant and anaesthetist services are calculated based on a unit system, comprising basic units plus time units. Anaesthesia basic units are 7. Assistant basic units are 6. See the Surgical Assistants' Services section starting on and Anaesthesiologists' Services section starting on for detailed calculation rules.
When to Use
- Use R418 for open synovectomy or debridement of the wrist joint when the procedure is limited to the wrist and does not involve formal arthrodesis or carpectomy.
- Select R418 when performing a debridement of inflamed synovial tissue in patients with rheumatoid arthritis or similar inflammatory arthropathies where formal joint reconstruction is not required.
Common Pitfalls
- Billing R418 in conjunction with more extensive procedures like R316 (Wrist arthrodesis) or R425 (Wrist arthroplasty) is considered unbundling; the more comprehensive procedure code should be used instead.
- Failure to document exact start and end times for the surgical assistant (suffix B) and anaesthesiologist (suffix C) will result in automatic rejection of the time-based unit claims.
- Attempting to bill R418 bilaterally without the appropriate bilateral indicator or modifier often leads to claim rejection or payment at 100% for only one side.
Billing Tips
- Ensure that the surgical report clearly distinguishes the debridement from any incidental procedures, as R418 is a flat-rate code and does not allow for additional 'add-on' debridement codes for the same anatomical site.
- Always verify the major procedure status when performing multiple surgeries under the same anaesthetic, as the basic units for the assistant and anaesthetist are dictated by the highest-valued procedure code.
Effective: April 1, 2025
N. Musculoskeletal System Surgical Procedures
MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES
Surgical
Musculoskeletal System Surgical Procedures
For Surgical Assistant (suffix B) and Anaesthesia (suffix C) services, the start and end times must be recorded in the patient's permanent medical record.
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