Radiopaedia’s Black Friday Course Sale ends Today!  SHOP NOW

Kellgren and Lawrence system for classification of osteoarthritis

Last revised by Dr Henry Knipe on 15 Sep 2021

The Kellgren and Lawrence system is a common method of classifying the severity of osteoarthritis (OA) using five grades. 

The original paper 1 graded OA at the following sites and projections:

  • hands: posteroanterior
  • cervical spine: lateral
  • lumbar spine (facet joints only): lateral
  • hips: anteroposterior
  • knees: anteroposterior
  • feet: anteroposterior

Classification

Numerous variations of the Kellgren and Lawrence classification system have been used in research 3. Below is the original description 1-3:

  • grade 0 (none): definite absence of x-ray changes of osteoarthritis
  • grade 1 (doubtful): doubtful joint space narrowing and possible osteophytic lipping
  • grade 2 (minimal): definite osteophytes and possible joint space narrowing
  • grade 3 (moderate): moderate multiple osteophytes, definite narrowing of joint space and some sclerosis and possible deformity of bone ends
  • grade 4 (severe): large osteophytes, marked narrowing of joint space, severe sclerosis and definite deformity of bone ends

Osteoarthritis is deemed present at grade 2 although of minimal severity 1

History and etymology

This classification was proposed by Kellgren and Lawrence in 1957 1 and later accepted by the World Health Organization (WHO) in 1961 as the radiological definition of OA for the purpose of epidemiological studies 3,4.

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Case 1: grade IV osteoarthritis
    Drag here to reorder.
  • Case 2: grade III
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.