articular step-off
A displacement of joint surface fragments creating an uneven articular contour that may lead to post-traumatic arthritis.
Full Definition
An articular step-off is a measurable displacement between fracture fragments at a joint surface, creating an irregular articular contour. This displacement disrupts the smooth articulation between bones and concentrates stress at the step-off location, potentially leading to cartilage wear and post-traumatic arthritis. The magnitude of acceptable step-off varies by joint location, with most authorities accepting 1-2mm displacement in weight-bearing joints. Reduction of articular step-offs is a primary goal in intra-articular fracture treatment, as even small irregularities can have significant long-term consequences for joint function.
Usage
Usage note: Always quantify step-off measurements in millimeters when documenting articular injuries.
In Context
- "Post-reduction CT showed a 3mm articular step-off that required revision fixation." — Radiology report
- "The goal of surgery was to reduce the articular step-off to less than 2mm to prevent post-traumatic arthritis." — Pre-operative planning note