# Kellgren-Lawrence — Kellgren-Lawrence radiographic grading of osteoarthritis

> Ordinal radiographic osteoarthritis morphology based on osteophytes, joint-space loss, subchondral sclerosis and bone-end deformity. The grade must be tied to a named joint, side, compartment, projection and description/atlas lineage; it does not diagnose symptomatic osteoarthritis, identify a pain generator or prescribe treatment.

**Situação:** vigente · **Órgão:** Musculoesquelético · **Órgão emissor:** Kellgren and Lawrence / musculoskeletal epidemiology · **Versão:** 1957 original; joint, projection and description lineage required · **Ano:** 1957

> ⚠️ Uma versão mais nova pode existir (em revisão).

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: XR
- Fonte primária: Kellgren JH, Lawrence JS. Radiological assessment of osteo-arthrosis (Kellgren and Lawrence) (1957) — https://doi.org/10.1136/ard.16.4.494
- Última verificação: 2026-07-24
- Última checagem: 2026-08-12

## Lógica de decisão
Grade radiographic morphology only after fixing joint, side, projection and description lineage; expose feature-level disagreement and never use the number as a proxy for pain, clinical diagnosis, prognosis or treatment need.

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| 0 | Grade 0, no radiographic OA features | On the named joint, side and technically adequate declared projection, no osteophyte, joint-space narrowing, subchondral sclerosis or bone-end deformity is identified under the stated Kellgren-Lawrence description. Grade 0 is not valid for an unseen compartment or an inadequately positioned image. | Report no radiographic OA features on the assessed view. If symptoms are typical, evaluate and manage the person clinically; grade 0 does not end the work-up. If symptoms are atypical, rapidly worsening or accompanied by a hot swollen joint, trauma or destructive change, pursue the appropriate alternative diagnosis rather than repeating KL grading. | Grade 0 is below the common epidemiologic threshold for definite radiographic knee OA, but it does not exclude pain, early or non-radiographic disease, patellofemoral disease missed on an AP view, or future OA. No individual progression or symptom probability is supplied by the grade. | Kohn et al. 2016, PMC4925407, Description of grade 0 and Limitations; Bedson and Croft 2008, PMC2542996, Results on clinical-radiographic discordance; NICE NG226 recommendations 1.1.1-1.1.2 and atypical-features definition. | ✓ |
| 1 | Grade 1, doubtful joint-space narrowing or possible osteophytic lipping | Doubtful joint-space narrowing and/or possible osteophytic lipping on the named joint and declared projection. The possible finding must be separated from projection, positioning and normal variation; when that cannot be done, preserve a 0-versus-1 boundary rather than claiming definite OA. | Describe the equivocal feature and acquisition limitations instead of treating grade 1 as a clinical diagnosis. Management remains based on symptoms and function, with information, therapeutic exercise and weight management when appropriate; routine imaging follow-up is not indicated solely to watch a KL number. | Grade 1 is commonly grouped with grade 0 as no or possible radiographic OA in knee research, but that convention is not a universal clinical threshold. It neither predicts pain nor provides a calibrated chance of progression to grade 2. | Kohn et al. 2016, PMC4925407, grade 1 description and threshold discussion; Schiphof et al. 2008, DOI 10.1136/ard.2007.079020, non-identical descriptions; NICE NG226 recommendations 1.2.2, 1.3.1 and 1.5.4. | ✓ |
| 2 | Grade 2, definite osteophytes with possible joint-space narrowing | Definite osteophyte formation with possible joint-space narrowing under the canonical knee description. A feature pattern with definite narrowing but no definite osteophyte exposes a known atlas/description ambiguity and must be reported with its lineage rather than silently forced into grade 2. | Record mild/definite radiographic OA morphology but do not diagnose symptomatic OA or select treatment from the image alone. For clinically diagnosed OA, guide care by pain, function, preferences and comorbidity; use exercise and weight management when appropriate, and do not routinely image for non-surgical follow-up. | Grade 2 or higher is a common epidemiologic definition of definite radiographic knee OA, not a universal proof of symptomatic disease. The category carries no fixed pain, progression, arthroplasty or survival probability for an individual. | Kohn et al. 2016, PMC4925407, grade 2 definition and definite-radiographic-OA threshold; Schiphof et al. 2008, DOI 10.1136/ard.2007.079020; Bedson and Croft 2008, PMC2542996; NICE NG226 recommendations 1.2.2 and 1.5.4. | ✓ |
| 3 | Grade 3, multiple osteophytes, definite narrowing, some sclerosis and possible deformity | Multiple or moderate osteophytes with definite joint-space narrowing, some subchondral sclerosis and possible deformity of the bone ends on the declared joint/projection. Confirm that narrowing is not chiefly a positioning or non-comparable-view artifact and name the affected compartment. | Report moderate radiographic morphology and separately document symptoms, function, alignment and alternative findings. The grade does not prescribe medication, injection or surgery. Consider joint-replacement referral only when symptoms substantially affect quality of life and non-surgical management is ineffective or unsuitable, using clinical assessment rather than this number alone. | Grade 3 establishes more advanced structural change than grade 2 but does not determine symptom intensity, treatment response or inevitability/timing of arthroplasty. Apparent longitudinal change is unreliable when views, loading or flexion differ. | Kohn et al. 2016, PMC4925407, grade 3 description and reliability limitations; NICE NG226 recommendations 1.5.4 and 1.6.1-1.6.2; Eijking et al. 2026, PMC12964767, interspecialty reliability results. | ✓ |
| 4 | Grade 4, large osteophytes, marked narrowing and sclerosis with definite deformity | Large osteophytes, marked or severe joint-space narrowing, marked or severe subchondral sclerosis and definite deformity of the bone ends on a technically adequate declared projection. Document compartment, alignment and any collapse or destructive feature that may require a separate diagnosis. | Report severe radiographic OA morphology, but do not equate it with unbearable pain or an automatic arthroplasty indication. Referral and treatment require clinical symptom/function burden, quality-of-life impact, prior non-surgical care, comorbidity, preferences and exclusion of urgent alternative pathology. | Grade 4 is the highest ordinal radiographic morphology category, not a prognosis or futility label. Some people have discordant symptoms, and the grade alone provides no individualized probability of disability, progression, surgical need or outcome. | Kohn et al. 2016, PMC4925407, grade 4 definition and Limitations; Bedson and Croft 2008, PMC2542996, symptom-radiograph discordance; NICE NG226 recommendations 1.6.1-1.6.3 and atypical-features definition. | ✓ |

### Citações por categoria
- **0**: Kohn MD, Sassoon AA, Fernando ND. Classifications in Brief: Kellgren-Lawrence Classification of Osteoarthritis (2016) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4925407/ · Kohn et al. 2016, PMC4925407, Description of grade 0 and Limitations; Bedson and Croft 2008, PMC2542996, Results on clinical-radiographic discordance; NICE NG226 recommendations 1.1.1-1.1.2 and atypical-features definition.
- **1**: Kohn MD, Sassoon AA, Fernando ND. Classifications in Brief: Kellgren-Lawrence Classification of Osteoarthritis (2016) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4925407/ · Kohn et al. 2016, PMC4925407, grade 1 description and threshold discussion; Schiphof et al. 2008, DOI 10.1136/ard.2007.079020, non-identical descriptions; NICE NG226 recommendations 1.2.2, 1.3.1 and 1.5.4.
- **2**: Kohn MD, Sassoon AA, Fernando ND. Classifications in Brief: Kellgren-Lawrence Classification of Osteoarthritis (2016) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4925407/ · Kohn et al. 2016, PMC4925407, grade 2 definition and definite-radiographic-OA threshold; Schiphof et al. 2008, DOI 10.1136/ard.2007.079020; Bedson and Croft 2008, PMC2542996; NICE NG226 recommendations 1.2.2 and 1.5.4.
- **3**: Kohn MD, Sassoon AA, Fernando ND. Classifications in Brief: Kellgren-Lawrence Classification of Osteoarthritis (2016) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4925407/ · Kohn et al. 2016, PMC4925407, grade 3 description and reliability limitations; NICE NG226 recommendations 1.5.4 and 1.6.1-1.6.2; Eijking et al. 2026, PMC12964767, interspecialty reliability results.
- **4**: Kohn MD, Sassoon AA, Fernando ND. Classifications in Brief: Kellgren-Lawrence Classification of Osteoarthritis (2016) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4925407/ · Kohn et al. 2016, PMC4925407, grade 4 definition and Limitations; Bedson and Croft 2008, PMC2542996, symptom-radiograph discordance; NICE NG226 recommendations 1.6.1-1.6.3 and atypical-features definition.

## Referências cruzadas
- _fronteira compartilhada_ → [Tönnis — Tönnis grading of hip osteoarthritis](https://radcommons.laudos.ai/systems/tonnis-hip.md) — Both can describe radiographic hip osteoarthritis, but Tonnis and Kellgren-Lawrence use distinct grade definitions and are not numerically interchangeable. Name the selected system and projection.

## Histórico de versões

| Data | Evento | Detalhe | Situação |
| --- | --- | --- | --- |
| 2026-07-25 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 1957-12-01 | published | Kellgren and Lawrence published the radiographic osteoarthrosis assessment framework. Later grade wordings vary, so current records must preserve the description or atlas lineage. | confirmed |


---
> Conteúdo de referência reescrito. Confira a publicação primária vigente. Não é dispositivo médico nem substitui o julgamento clínico. O radiologista responsável pelo laudo permanece o autor e o responsável.

Página HTML: https://radcommons.laudos.ai/systems/kellgren-lawrence · JSON da API: https://radcommons.laudos.ai/api/v1/systems/kellgren-lawrence · Índice para agentes: https://radcommons.laudos.ai/llms.txt