About Knee Osteoarthritis

Knee osteoarthritis (OA) is a prevalent, chronic joint condition characterized by progressive articular cartilage degeneration, subchondral bone remodeling, and varying degrees of synovial inflammation. It commonly presents with activity-related knee pain, stiffness after periods of rest, functional limitation, and crepitus, with symptoms often exacerbated by prolonged weight-bearing, stair use, or deep knee flexion.

The etiology of knee OA is multifactorial and reflects the interaction of age-related tissue changes, previous knee injury, biomechanical factors (e.g., malalignment), excess body mass, muscle weakness, metabolic factors, and cumulative mechanical loading. Structural changes do not consistently correlate with symptom severity or functional impact, and clinical presentation varies widely across individuals.

Knee OA affects physical function, participation in daily life, and quality of life, with outcomes influenced by biological, psychological, and social factors.

About CCG Care Pathways

Purpose

CCG is a knowledge translation resource of the Canadian Chiropractic Association. Its care pathways help chiropractors and other clinicians organize conservative care for musculoskeletal conditions. Each pathway outlines the main steps of the clinical encounter and supports decisions about assessment, care, monitoring, referral, co-management, and discharge. The pathways provide a structured approach to care, not a fixed prescription.

Development

Pathways draw on relevant clinical practice guidelines, systematic reviews, peer-reviewed literature, and safety or professional sources. These sources inform, but do not determine, pathway content. Their findings reflect the questions, populations, outcomes, methods, and judgments used and may not apply to every person. Condition-specific sources are identified by author or organization and year, with full citations in one reference list at the end of the pathway.

Principles of Care

Musculoskeletal conditions are shaped by physical, psychological, social, cultural, and environmental factors, so no single approach fits everyone. Good care is ethical, evidence-informed, person-centred, culturally responsive, and tailored to the patient’s goals, preferences, circumstances, and response. Shared decision-making and informed consent guide care. Education, active rehabilitation, and self-management support recovery, functioning, participation, and long-term health. Regular reassessment shows whether the plan is helping and when to continue, adapt, stop, refer, co-manage, or discharge.populations.

Pathway Flow at a Glance

The pathway follows a recurring clinical cycle: understand the person and their goals; screen for safety and referral needs; develop a working clinical profile; agree on a plan and relevant outcomes; provide care; reassess response and safety; and continue, adapt, stop, refer, co-manage, or discharge as appropriate.

Disclaimer

CCG care pathways support professional clinical judgment; they do not replace it or the advice of a qualified provider. They are not prescriptive, authoritative, or regulatory and are not intended for diagnosis or billing. Clinicians remain responsible for practicing within their competence and scope, meeting applicable legal and regulatory requirements, obtaining informed consent, recognizing emergencies, and arranging referral or co-management when needed.

Knee Osteoarthritis Care Pathway

1. Record Keeping

Accurate, timely, and sufficiently detailed documentation supports safe, high-quality care. The record should reflect clinically relevant patient interactions, clinical reasoning, decisions, care provided, and progress over time. Documentation should meet the legal, regulatory, privacy, retention, and organizational requirements that apply where the clinician practices. A structured format, such as SOAP, may support consistency, clarity, and continuity and can be adapted to the encounter and practice setting.

Subjective: Record the patient’s concerns, symptoms, functioning and participation, goals, preferences, relevant history and context, and response or adverse effects from previous care.

Objective: Record relevant examination findings, outcome measures, diagnostic test results when available, and clinically important changes.

Assessment: Record the clinical interpretation of findings, working diagnosis or clinical profile, differential and safety considerations, relevant risk factors or modifiers, and the patient’s progress or response.

Plan: Record care provided or proposed, education and self-management, consent and patient decisions, changes to the plan, agreed outcomes and reassessment point, referrals or co-management, follow-up, and discharge planning.

Document at the time of the encounter or as soon as practicable. Corrections and additions should preserve the integrity of the record. Clear records support patient safety, shared decision-making, communication, continuity, and accountability.

2. Informed Consent

Definition: A continuing process in which a capable patient, or an authorized substitute decision-maker when required, voluntarily agrees to a proposed examination or intervention after receiving and understanding the information needed to make an informed choice.
Key Aspects:
- Prior to interaction: Obtain consent before beginning an examination, procedure, or treatment, except where applicable law permits otherwise. Explain what is proposed and why. Revisit consent when the plan or material information changes.
- Voluntarily and specific: must be voluntary and specific to the proposed care. Consider the patient’s capacity for the decision at the time it is required and follow applicable requirements for substitute decision-making when the patient lacks capacity. The patient may ask questions, refuse, place limits on, or withdraw consent.
- Transparent process: Use honest, plain, and accessible communication. Offer interpretation or other communication support when needed and consider language, culture, health literacy, disability, and prior trauma. Written or digital information may support but does not replace discussion.
- Patient understanding and agreement:
  - Diagnosis/prognosis: Explain relevant findings, the clinical impression or working diagnosis, important uncertainty, and the expected course in understandable language.
  - Treatment plan: Discuss the nature and purpose of proposed care, expected benefits, material risks and side effects, burdens, reasonable alternatives, the option of no intervention, and the likely consequences of accepting or declining.
  - Questions: Invite questions, explore goals and preferences, allow appropriate time for a decision, and confirm understanding, for example using teach-back.
- Documentation: Record the consent discussion and decision, including material information provided, questions, capacity or substitute decision-maker where relevant, consent, refusal, limits or withdrawal, and any need to revisit consent. Follow documentation requirements applicable to the jurisdiction and practice setting.

3. Health History

Apply cultural awareness and trauma-informed care principles.
Sociodemographic information: Age, gender, sex, race/ethnicity.
Main complaint: Description of knee pain, stiffness, swelling, symptom behavior, aggravating and easing factors, and functional limitations.
Body systems: Neurologic, cardiovascular, genitourinary, gastrointestinal, musculoskeletal, bone density, eyes/ears/nose/throat, respiratory, skin, mental health, reproductive.
Health, lifestyle, and history: Past medical conditions, medications, supplements, prior knee injury or surgery, hospitalizations, physical activity and exercise history, occupational demands, diet, sleep habits, footwear, and work or school environment.
Social determinants of health: Employment, childcare, education, nutrition, housing, domestic violence, child maltreatment, discrimination, social isolation.
Previous treatments and responses: Prior conservative or medical treatments, perceived benefit, adherence, and adverse effects.
Beliefs and expectations: Understanding of knee OA, expectations regarding recovery and care, concerns about progression or activity participation.
Flag considerations: Screen for red flags, orange flags, and psychosocial (yellow) factors.

Outcomes Assessments:

Pain: Use pain scales (e.g., NRS) and diagrams.
Function and Participation: Evaluate impact on daily activities (PSFS, WHODAS, WOMAC).
Recovery: Use self-rated recovery scales.
Quality of life: Assess using tools such as SF-12.
Work/school status: Monitor return to activities.
Individual goals: Set SMART goals (Specific, Measurable, Achievable, Relevant, Timely).
Patient feedback: Gather and integrate patient experience and satisfaction.

4. Red Flags : Differential Diagnosis Requiring Medical Referral

ACTION: Refer immediately to emergency care:

Trauma / fracture: Sudden onset following trauma, inability to bear weight, deformity, or hemarthrosis, particularly in individuals with diminished bone integrity.
Infection: Suspected septic arthritis or osteomyelitis presenting with acute monoarticular pain, swelling, warmth, fever, inability to bear weight, or severe pain with passive motion.
Deep vein thrombosis: Posterior knee or calf pain, unilateral swelling, warmth, or edema.

ACTION: Refer to appropriate medical provider:

Inflammatory arthritis: Suspected reactive arthritis or rheumatoid arthritis.
Avascular necrosis or other bone pathology: Progressive pain and functional decline not consistent with typical OA presentation.

5. Orange Flags: Symptoms of Psychiatric Disorders Requiring Referral

Orange Flags are signs that a mental health or substance use concern may require emergency or timely assessment or shared care, and may change whether and how MSK care proceeds. They are not diagnoses. Ask directly and respectfully when concern arises, considering immediate safety, severity, change from usual, daily functioning and context. Psychosocial factors that may affect recovery but do not require separate mental health or medical assessment are addressed under Yellow Flags.

ACTION: Arrange emergency assessment now when there is immediate danger or an urgent medical need:

Suicide, self-harm or harm to others: current intent or plan, a recent attempt, inability to stay safe, or behaviour suggesting an immediate risk of serious harm.
Severe change in mental state: extreme agitation, confusion, disorganization, possible psychosis or mania with impaired judgment or unsafe behaviour, or inability to meet basic needs when this creates immediate danger.
Substance-related or medical emergency: suspected overdose, severe intoxication, dangerous withdrawal, delirium or another sudden change requiring urgent medical care.

When immediate safety is uncertain, do not leave the person alone while help is arranged. Follow local emergency procedures and call 9-1-1 for immediate danger or urgent medical need. If the person is thinking about suicide, call or text 9-8-8: Suicide Crisis Helpline with them or support them to do so.

If violence, abuse or exploitation is disclosed or suspected, support immediate safety and follow applicable safety and reporting requirements.

ACTION: Arrange prompt medical or mental health assessment when there is:

Suicide or self-harm thoughts: thoughts without immediate danger.
Substantial symptoms or effects: severe, persistent or worsening symptoms of depression, anxiety, trauma, possible psychosis or mania, eating problems or substance use that substantially affect daily life, decision-making or safe participation in care.
Other reasons for assessment: a marked change from usual behaviour or functioning; concern about medication or substance effects; a presentation outside the clinician’s competence; or a request for help.

Agree with the patient on who will be contacted, how soon and what to do if the situation worsens. Confirm that the person has connected with the service when clinically important.

ACTION: Adapt and coordinate MSK care:

Safe care: care may continue when it is safe and acceptable and does not delay needed assessment. Adapt communication, examination and care; obtain ongoing consent; and coordinate with other providers with the patient’s permission.
Continue the MSK assessment: do not assume that a mental health or substance use concern explains the MSK presentation. Continue to consider physical causes and the patient’s account.
Questionnaires: they may support conversation and monitoring, but do not establish a diagnosis or replace direct questions, clinical judgment or action.
Acceptable support: ask what type of help is acceptable and whether language, cultural, family, community or other supports are important to the patient.

ACTION: Document and follow up:

Record the concern; relevant questions and the patient’s responses; the safety decision and reasons; actions, advice and referrals; communication and consent; follow-up; and any unresolved concern. Follow applicable privacy, safety and reporting requirements.

For provincial, territorial and national services, see Mental health support: Get help (Public Health Agency of Canada 2026).

6. Yellow Flags: Factors that May Affect Recovery or Participation

Yellow Flags are personal, social, work, school, healthcare, environmental or structural factors that may influence symptoms, functioning, participation or response to care. They are contextual, not diagnoses or certain predictions, and do not mean that symptoms are psychological. They guide how care is tailored and do not by themselves require urgent referral. Explore them through conversation and ongoing outcome review, with attention to the patient’s priorities, strengths and circumstances. A separate Yellow Flag score is not required. New or worsening signs of serious physical illness follow the Red Flag process. Mental health or substance use concerns that need separate assessment, or any immediate safety concern, follow the Orange Flag process and applicable emergency or safeguarding procedures.

Explore relevant factors:

Understanding, expectations and healthcare experiences: concerns about injury or damage, uncertainty, recovery expectations, confidence, conflicting advice, previous dismissal or harm, and trust in care.
Responses to symptoms and activity: worry, fear, avoidance, cycles of doing too much and then needing prolonged rest, difficulty pacing, coping, sleep, confidence in self-management, and return to meaningful activities.
Emotional and life context: distress, low mood, anxiety, grief, trauma, caregiving, relationship change, job loss or other major events. Ask permission before sensitive questions and limit discussion to what is relevant and acceptable to the patient.
Relationships, culture and strengths: supportive relationships, isolation, family and community roles, cultural or spiritual practices, identity, preferences, language and other sources of resilience.
Work, school and administrative context: physical and psychosocial demands, control, satisfaction, job security, accommodations, return concerns, and compensation, insurance or legal processes. Explore these neutrally and in context.
Social and structural conditions: consider social and structural determinants of health (Public Health Agency of Canada 2026), including income, housing, food security, transportation, childcare, access and cost of care, discrimination, racism, colonialism, neighbourhood and workplace conditions, and physical or digital accessibility.

ACTION: Respond with the patient:

Ask, do not assume: use open questions to understand what helps, what gets in the way, what matters and what feels feasible. Ask about strengths and protective factors, not only difficulties. Do not treat a person’s circumstances, culture or choices as a deficit.
Plan together: integrate relevant findings into shared goals, education, self-management, physical activity or exercise, and participation in meaningful activities. Adapt communication, setting, pace, cost and access where possible.
Connect and coordinate: with the patient’s consent, consider appropriate clinical, social, workplace, school, community, Indigenous or culturally specific supports. Clarify who will do what and follow up when the connection is important to the plan.
Review response to care: reassess the patient’s account and the pathway’s selected outcomes at clinically relevant points. If progress differs from expected, review the clinical impression, care plan, access and other barriers; do not automatically attribute the outcome to Yellow Flags.
Document: record relevant factors and strengths, the patient’s priorities and preferences, agreed actions, consent, referrals or coordination, follow-up, and any change requiring the Orange Flag process.

7. Physical Examination

Observation: Posture, alignment, swelling, muscle bulk, gait pattern, balance, and functional movement strategies.
Range of motion (ROM): Assess active, passive, and resisted knee ROM in flexion, extension, internal rotation, and external rotation.
Palpation: Examine for joint line tenderness, swelling, tightness, or temperature changes, and soft tissues of the knee region.
Neurological examination: Performed when neurological symptoms are reported or suspected.
Special/Orthopedic Tests: Perform as clinically indicated.
Advanced Diagnostics: Radiography is indicated if Ottawa Knee Rules criteria are met. Otherwise, radiography is not typically indicated. Advanced imaging may be considered in complicated or refractory cases.

8. Clinical Presentation for Knee Osteoarthritis (Altman et al., 1986)

Knee OA commonly presents with activity-related knee pain, stiffness after periods of inactivity (typically <30 minutes), functional limitation, and crepitus. Symptoms may fluctuate over time and vary in severity.

Common clinical features include:

Knee pain aggravated by weight-bearing activities, stair use, or prolonged activity
Morning or post-rest stiffness of short duration
Reduced knee range of motion
Functional difficulty with walking, transfers, or stair negotiation
Variable joint swelling or effusion
Crepitus during knee movement
Bony enlargement or localized tenderness
Absence of marked joint warmth

Structural severity on imaging does not reliably predict pain intensity, functional limitation, or symptom burden.

Clinical classification of knee OA may be informed by established criteria (e.g., Altman criteria); however, diagnosis is primarily clinical and should be interpreted in the context of the individual’s symptoms, function, and goals.

9. Conservative Treatment Considerations for Knee Osteoarthritis (Kolasinski et al., 2019)

Approach to Treatment

The treatments outlined in this section reflect core domains of care consistently identified across high-quality clinical practice guidelines and established clinical practices. These include interventions shown to improve patient-important outcomes such as pain, function, and quality of life. Management plans should be tailored to the individual’s needs, goals, and preferences, taking into account clinical presentation, response to care, and contextual factors.

Not all domains need to be included in every care plan or at every stage of recovery. Clinicians are expected to apply professional judgment in selecting the most relevant components based on the clinical context.

This pathway is not prescriptive, nor does it list every possible intervention. Readers are encouraged to consult individual guidelines for specific treatment protocols, dosage, and condition-specific considerations.

While a range of other interventions may be in use, such as passive physical modalities, these have mixed or limited evidence of clinical benefit and are therefore not recommended for routine use. If applied, such therapies should be used as adjuncts to the core, evidence-based components of care, and not as standalone treatment.

Strong recommendations

Exercise
- Regular land-based or aquatic exercise, delivered in supervised or independent formats.
Self-efficacy and self-management programs
- Multidisciplinary, group–based programs incorporating skill-building (e.g., goal setting, problem-solving, positive thinking), education about osteoarthritis and medications, joint protection strategies, and fitness and exercise planning.
Weight loss interventions
- Recommended for individuals who are overweight or obese, as even modest weight reduction is associated with clinically meaningful improvements in pain and function.
Tai Chi
- A mind-body practice combining slow, controlled movements, balance, breathing, and relaxation.
Cane
- Recommended when knee OA significantly affects ambulation, joint stability, or pain, warranting use of an assistive device.
Tibiofemoral knee brace
- Recommended when knee OA substantially affects ambulation, joint stability, or pain, and when the individual can tolerate the burden associated with bracing.
Topical/oral NSAIDs
- For pain management, with selection guided by individual risk factors and preferences.
Intra-articular corticosteroid injections
- For short-term relief of pain and inflammation.

Conditional recommendations

Heat or therapeutic cooling
- Adjunctive modalities for short-term relief of pain and stiffness.
Cognitive behavioural therapy
- To improve pain, function, and quality of life by addressing maladaptive pain-related thoughts and behaviors.
Acupuncture
- Evidence suggests small improvements in pain and function, with effects potentially influenced by contextual and placebo-related factors.
Kinesiotaping
- A short-term adjunct to reduce pain and improve function; benefits are modest and evidence quality is limited.
Balance training
- As part of an exercise program to improve proprioception, reduce fall risk, and enhance functional performance.
Patellofemoral knee brace
- Recommended when knee OA significantly affects ambulation, joint stability, or pain, warranting use of an assistive device.
Yoga
- A mind–body intervention combining physical postures, breathing techniques, and relaxation or meditation
Radiofrequency ablation
- Recommended in selected individuals with persistent pain; may provide longer-lasting analgesia than intra-articular injections, though evidence is limited.
Acetaminophen, duloxetine, tramadol
- Acetaminophen: conditionally recommended for short-term or episodic use.
- Duloxetine: conditionally recommended for chronic knee OA pain.
- Tramadol: conditionally recommended only when other therapies are ineffective or contraindicated due to safety concerns.
Topical capsaicin
- May provide modest pain relief through peripheral nociceptor desensitization; local skin irritation is the most common adverse effect.

10. Risk and Prognostic Factors for Knee OA (Berteau et al., 2022; Zheng et al., 2015; de Rooij et al., 2016; Bastick et al., 2015)

The development, symptom burden, and progression of knee osteoarthritis (OA) are influenced by a combination of biological, mechanical, psychological, and social factors. Identification of these factors supports realistic goal setting, individualized care planning, and appropriate monitoring over time.

Risk factors

Non-modifiable factors
- Increasing age
- Female sex
- Genetic predisposition
- Race/ethnicity, reflecting differences in OA prevalence, symptom severity, and access to care
Prior joint injury or surgery
- History of knee trauma (e.g., ligament or meniscal injury)
- Previous knee surgery
Mechanical and biomechanical factors
- Malalignment (varus or valgus)
- Abnormal joint loading patterns
- Muscle weakness, particularly of the quadriceps
- Reduced neuromuscular control
Body weight and metabolic factors
- Overweight or obesity
- Metabolic conditions associated with systemic inflammation
Occupational and activity-related factors
- Repetitive or sustained knee loading
- Occupations or activities involving frequent kneeling, squatting, or heavy lifting
Psychological and social factors
- Depression, anxiety, or pain catastrophizing
- Low self-efficacy
- Limited social support
- Barriers related to access to care or resources

Prognostic considerations

Knee OA has a variable and often fluctuating clinical course, and symptom severity does not reliably correlate with radiographic findings.
Many individuals experience meaningful improvements in pain, function, and quality of life with appropriately matched conservative care.
Persistent pain or functional limitation is more likely in the presence of:
- High baseline pain or disability
- Obesity or low physical activity levels
- Psychological distress or maladaptive pain beliefs
- Multiple comorbidities
- Adverse social determinants of health
Engagement in physical activity, adherence to exercise and self-management strategies, and alignment of care with patient goals are associated with more favourable outcomes.

11. Ongoing Follow-up

Ongoing follow-up is a shared review of whether the plan remains safe, useful, acceptable and aligned with the patient’s goals. The timing of review should reflect symptoms, risk, the care being tried, goals and access rather than a fixed visit schedule.

Review symptoms and safety: ask what has changed in symptoms, functioning and daily activities; review adverse effects; and check for new or worsening Red Flags and relevant Orange or Yellow Flag concerns. Arrange earlier or urgent assessment when the findings require it.
Review outcomes: repeat the small set chosen at baseline and use the same measures when possible. These may include the Patient-Specific Functional Scale, WHODAS 2.0, quality of life using the patient’s own rating or a measure such as WHOQOL-BREF, symptom impact, participation and the patient’s own assessment of change. Interpret measures with the patient and alongside what has changed in daily life rather than relying on a score alone.
Review goals, preferences and consent: ask whether care remains acceptable, feasible and worthwhile; revisit goals and priorities; and confirm consent when the plan or circumstances change.
Adapt care: continue what is useful and acceptable, and change, pause or stop what is not. If progress is not sufficient from the patient’s perspective, review the clinical impression, the fit and amount of care, barriers to participation, other health or social factors and whether other expertise is needed.
Support self-management and participation: review the strategies the patient is using, including physical activity or exercise, symptom management, pacing and participation in work, school, caregiving, recreation or community life. Ask what is helping and which barriers can be addressed.
Referral and co-management: arrange emergency assessment for Red Flags requiring urgent care. Consider referral or co-management when findings or needs are beyond the clinician’s role, the patient’s condition is worsening, progress remains insufficient after the plan has been reviewed, or the patient requests another opinion.
Plan the next step: agree whether to continue, change the interval between visits, move toward more self-directed care, or apply the Criteria for Discharge section.

12. Criteria for Discharge

Discharge is a shared decision about ending or transferring a course of care. It does not require complete symptom resolution, a normal outcome score or a fixed number of visits.

When discharge may be appropriate: consider discharge when the patient’s goals have been met to a degree they consider satisfactory; the patient feels able to manage with less or no clinician involvement; the patient chooses to end care; continued care is not providing enough benefit to justify its burden, cost or time; or care is being transferred to another provider.
Reassess before discharge: review symptoms, functioning, participation, selected outcomes, goals, adverse effects, confidence and preferences. Check for new or worsening Red Flags and any Orange or Yellow Flag concerns that still require action. If the condition is worsening or a safety concern remains, arrange the required assessment or referral rather than routine discharge.
When progress has slowed: review the clinical impression, response to care, goals, barriers and access, other health or social factors, and other reasonable options before deciding with the patient whether to continue, change or end care.
Plan after discharge: agree on self-management, physical activity or exercise, symptom management, pacing and participation in work, school, caregiving, recreation or community life. Explain which changes should prompt earlier or urgent assessment and when and where to seek care.
Future access to care: explain how the patient can return if symptoms recur, functioning declines, or goals or demands change. Any planned future review or supportive care should have an agreed purpose, expected benefit and review point.
Referral or transfer: explain the reason, share a relevant summary with the patient’s consent, and clarify who will address outstanding concerns when possible. Avoid an unintended gap in care when safety or ongoing needs remain.
If the patient ends care or does not return: respect the patient’s right to stop. Record what is known and unknown about the outcome, advice or referral offered, attempts to communicate when clinically warranted, and any unresolved safety concern. Follow applicable record keeping and communication requirements.
Documentation: record the reason care ended, the patient’s status and selected outcomes, goals and preferences, unresolved concerns, advice and self-management plan, referral or transfer details, and how to seek care again if needed.

Knee Osteoarthritis