Kellgren and Lawrence system for classification of osteoarthritis

Last revised by Henry Knipe on 20 Apr 2024

Citation, DOI, disclosures and article data

Citation:

Pai V, Knipe H, Rock P, et al. Kellgren and Lawrence system for classification of osteoarthritis. Reference article, Radiopaedia.org (Accessed on 23 Apr 2024) https://doi.org/10.53347/rID-27111

DOI:

https://doi.org/10.53347/rID-27111

Permalink:

https://radiopaedia.org/articles/27111

rID:

27111

Article created:

21 Jan 2014, Vivek Pai

Disclosures:

At the time the article was created Vivek Pai had no recorded disclosures.

View Vivek Pai's current disclosures

Last revised:

20 Apr 2024, Henry Knipe ◉ ◈

Disclosures:

At the time the article was last revised Henry Knipe had the following disclosures:

Integral Diagnostics, Shareholder (ongoing)
Micro-X Ltd, Shareholder (ongoing)

These were assessed during peer review and were determined to not be relevant to the changes that were made.

View Henry Knipe's current disclosures

Revisions:

24 times, by 11 contributors - see full revision history and disclosures

Systems:

Musculoskeletal

Sections:

Classifications

Tags:

osteoarthritis, cases

Synonyms:

Kellgren & Lawrence system for classification of osteoarthritis of knee
Kellgren & Lawrence system for classification of osteoarthritis in the knee
KL classification

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, 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 ¹and later accepted by the World Health Organisation (WHO) in 1961 as the radiological definition of OA for the purpose of epidemiological studies ^3,4.