E933 – Orbit - open reduction rim/wall fracture - Zygomatic fracture dislocation - with mini-plate(s), per major fracture line
OHIP Surgical Assists Code — MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES · Schedule of Benefits
This is an add-on code to be billed in addition to the primary procedure E173 for the open reduction of a zygomatic fracture dislocation. It is payable when miniplate(s) are used for fixation. The fee is claimed per major fracture line. The note on page of the Schedule of Benefits provides guidance on what constitutes a major fracture line: '...one mini-plate fee per each major fracture line (e.g. infraorbital, malar-zygomatic, nasal-frontal, LeFort I, LeFort II and III) (per major fracture line per side) should be billed.'
When to Use
- Use E933 when performing open reduction of a zygomatic fracture (E173) where fixation is achieved using mini-plates at distinct anatomical fracture sites.
- Apply this code for each additional major fracture line requiring independent mini-plate fixation, such as separate infraorbital and malar-zygomatic sites.
Common Pitfalls
- Billing E933 as a standalone procedure; it is strictly an add-on code and will be rejected if not submitted with the primary procedure E173.
- Over-billing by claiming multiple units for a single fracture line; the fee is per major fracture line, not per individual plate used at the same site.
- Failing to specify the number of units when multiple major fracture lines are fixed, which leads to underpayment.
Billing Tips
- Ensure the number of units billed for E933 corresponds exactly to the number of major fracture lines documented as requiring mini-plate fixation.
- Always link E933 to the primary E173 service on the same claim to avoid automatic rejection for missing primary procedure.
Effective: April 1, 2025
N. Musculoskeletal System Surgical Procedures
MUSCULOSKELETAL SYSTEM SURGICAL PROCEDURES
Procedure
Musculoskeletal System Surgical Procedures
Where mini-plate(s) are used, one mini-plate fee per each major fracture line (e.g. infraorbital, malar-zygomatic, nasal-frontal, LeFort I, LeFort II and III) (per major fracture line per side) should be billed.
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