Non-Traumatic Anterior Knee Pain Care Pathway

4. Differential Diagnosis Requiring Medical Attention

 

Red Flags: Immediate Referral to Emergency Care:

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1. Deep Vein Thrombosis (DVT)

• Pain Location: Throbbing pain in calf or thigh.

• Signs/Symptoms/Red Flags: Active cancer, paralysis/paresis/recent plaster immobilization of lower extremity, recently bedridden for 3 days, major surgery within 12 weeks requiring general anesthesia, previous DVT, shortness of breath, chest pain.

• Physical and Neurological Examination: Warmth, localized tenderness along distribution of deep veins, entire leg swollen, no neurological deficits.

• Action: Immediate referral to emergency care.

 

2. Infection (i.e., Septic arthritis)

• Pain Location: Localized pain in the knee area.

• Signs/Symptoms/Red Flags: Severe acute pain; erythema, warmth, and edema around knee joint; night sweats; night pain, recent trauma/surgery, intravenous drug use, fever, chills, reduced joint mobility.

• Physical and Neurological Examination: Diffuse tenderness, warmth to touch, edema, no neurological deficits.

• Action: Immediate referral to emergency care.

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Refer to Medical Provider:

 

1. Peripheral Arterial Disease (PAD)

• Pain Location: Leg pain/cramping while walking, often in calves.

• Signs/Symptoms: Cold lower extremities; history of coronary heart disease, cerebrovascular disease, diabetes, hypertension, hypercholesterolemia; family history of PAD; smoking; previous vascular problems; cancer; COPD; previous thromboembolic events.

• Physical and Neurological Examination: Absent/weak pulses in lower extremities, skin colour changes, sores on feet, leg numbness/ weakness.

• Action: Referral to appropriate medical provider.

 

2. Inflammatory Arthritides (rheumatoid arthritis, reactive arthritis, gout)

1. Rheumatoid Arthritis

• Pain Location: Various joints, often symmetrical, including the knee.

• Signs/Symptoms: Morning stiffness > 1 hour; symmetrical joint pain; joint swelling and deformity; systemic symptoms such as fatigue or malaise..

• Physical and Neurological Examination: Swollen, tender joints; deformities in severe cases; no neurological deficits.

• Action: Referral to appropriate medical provider.

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2. Reactive Arthritis

• Pain Location: Various joints, often including the knee.

• Signs/Symptoms: Joint pain and swelling following an infection; symptoms may include conjunctivitis and urethritis; systemic symptoms such as fatigue.

• Physical and Neurological Examination: Swollen, tender joints; no neurological deficits.

• Action: Referral to appropriate medical provider.

 

3. Gout

• Pain Location: Typically affects the big toe but can also involve the knee and other joints..

• Signs/Symptoms: Sudden onset of severe pain; redness; swelling; warmth in the affected joint; recurrent attacks; history of hyperuricemia.

• Physical and Neurological Examination: Extremely tender, swollen, and warm joint; red or purplish skin around the affected joint; no neurological deficits.

• Action: Referral to appropriate medical provider.

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3. Referred Pain

1. Slipped Capital Femoral Epiphysis (SCFE)

• Pain Location: Referred knee pain from hip joint pathology.

• Signs/Symptoms: Pain with activity and relief with rest; typically occurs in adolescence or late childhood.

• Physical and Neurological Examination: Walking or running with a limp, toe-out gait, or leg length discrepancy; no neurological deficits.

• Action: Referral to appropriate medical provider.

 

2. Hip Osteoarthritis

• Pain Location: Referred knee pain from the hip.

• Signs/Symptoms: Hip pain and stiffness; groin pain; pain with weight-bearing activities.

• Physical and Neurological Examination: Reduced range of motion in the hip; antalgic gait; no neurological deficits.

• Action: Referral to appropriate medical provider.

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3. Lumbar Radiculopathy

• Pain Location: Referred pain from the lower back to the knee.

• Signs/Symptoms: Lower back pain; radiating pain to the knee; numbness or tingling in the leg.

• Physical and Neurological Examination: Positive straight leg raise test; neurological deficits such as weakness or altered sensation.

• Action: Referral to appropriate medical provider.

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4. Tumor (e.g., Giant cell tumor)

• Pain Location: Knee or surrounding areas.

• Signs/Symptoms: Noticeable lump; pain that worsens with movement; swelling.

• Physical and Neurological Examination: Palpable mass; tenderness over the affected area; no neurological deficits.

• Action: Referral to appropriate medical provider.

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5. Peripheral Neuropathy

Saphenous nerve (i.e., Saphenous Neuritis or Gonalgia Paresthetica)

• Pain Location: Anterior or medial knee pain.

• Signs/Symptoms: Occasionally described as pain to touch along the nerve. Can be activity-related pain or pain at rest.

• Physical and Neurological Examination: Aggravated by limb movements that tension the nerve; sensory deficits along the distribution of the saphenous nerve.

• Action: Referral to appropriate medical provider.