Knee · General Health

Cartilage injury

Articular cartilage damage is graded arthroscopically from normal through softening and fissuring to full-thickness loss exposing subchondral bone.

What you are actually deciding

Record the lesion diameter as well as the grade — the Outerbridge II and III boundary is defined purely by size, and size drives the treatment decision more than the grade label. For cartilage repair research the ICRS system grades by depth and is preferred.

Patient-reported outcome measure1

Tegner Calculator1 items
Tegner Activity ScaleThe Tegner Activity Scale is a single-item ordinal ladder that grades a patient's work and sport activity from 0 (sick leave or disability pension because of knee problems) to 10 (national or international elite competitive sport), and is normally recorded twice — the pre-injury level and the current level — so that the drop between them can be reported.

Classification system1

Outerbridge Classification1 items
Outerbridge Classification of Chondral LesionsThe Outerbridge classification grades articular cartilage damage from 0 to IV at arthroscopy, progressing from normal cartilage through softening, fissuring under and over 1.3 centimetres in diameter, to full-thickness erosion exposing subchondral bone.

Thresholds that apply here

Published change thresholds across the instruments above. Check the population matches your patient before using a value — a threshold derived in a different cohort will mislead you.

Instrument	Type	Value	Subscale	Population
Tegner	MCID	1 activity level	—	Patients with anterior cruciate ligament injury

See the full threshold database for every instrument on the site.

Patient-reported outcome measure1

Classification system1

Thresholds that apply here

Related conditions