R421 – Synovectomy, capsulectomy, or debridement
OHIP Radiology Code — MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES · Schedule of Benefits
Synovectomy/capsulectomy/debridement, etc. R421 is a surgical procedure listed in the Musculoskeletal System section of the Schedule of Benefits. As a major surgical procedure, payment is eligible for the surgeon (suffix A), a surgical assistant (suffix B), and an anaesthetist (suffix C). The fees for assistants and anaesthetists are calculated based on a combination of basic units and time units, as detailed in the General Preamble (-). Various premiums may apply, including those for age (), after-hours services (, , ), and trauma ().
When to Use
- Use R421 for the surgical excision of inflamed synovial tissue or joint capsule in a major joint when no other specific joint-site code is more appropriate.
- Use R421 for the debridement of necrotic or infected tissue within a joint space that does not meet the criteria for more complex reconstructive or arthroplasty codes.
Common Pitfalls
- Billing R421 in conjunction with other definitive surgical procedures on the same joint often triggers a 'multiple procedure' rejection; ensure you are not unbundling a more comprehensive procedure.
- Failing to document the specific anatomical site and the extent of the debridement/synovectomy can lead to audit recovery if the service is deemed insufficiently described for a major surgical fee.
Billing Tips
- If performing R421 alongside a more major procedure on the same joint, verify if the Schedule of Benefits considers R421 an 'incidental' component of the primary surgery, which would preclude separate billing.
- Always append the appropriate surgical assistant (suffix B) and anaesthetist (suffix C) codes if applicable, as R421 is recognized as a major surgical procedure eligible for these additional claims.
Effective: April 1, 2026
N. Musculoskeletal System Surgical Procedures
MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES
Surgical
Musculoskeletal System Surgical Procedures
All insured services must be documented in appropriate records that establish: an insured service was provided, the service for which the account is submitted is the service that was rendered, and the service was medically necessary.
The information in this record is derived from the Master Fee Record and the General Preamble rules applicable to all surgical procedures.
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