A4Medicine

Knee pain is a prevalent and growing public health concern, particularly among adults, making it one of the most frequent reasons for primary care consultations. Research indicates that nearly 25% of Americans over the age of 55 experience chronic knee pain, with osteoarthritis (OA) being the leading cause (Hunter et al., 2022). This condition not only contributes to reduced mobility and disability but also imposes significant financial burdens, with knee OA-related medical costs surpassing $80 billion annually (Shema-Shiratzky et al., 2023).

As the aging population continues to rise, primary care providers play a critical role in early diagnosis, risk assessment, and effective management of knee pain. While osteoarthritis accounts for approximately 13.8% of cases, other contributing factors include previous knee injuries, inflammatory conditions, and psychosocial influences (Bedenbaugh et al., 2021; Sugai et al., 2018). Risk factors such as age, obesity, and prior trauma can negatively impact treatment outcomes, making a comprehensive and multidisciplinary approach essential for optimal patient care (Collier et al., 2023).

Knee Pain Triage Questionnaire

1. General Information

Age: Weight (kg): Height (cm): Medical Conditions (e.g., diabetes, arthritis, prior injuries): Previous Knee Surgery or Joint Procedures: History of Trauma or Injury (Describe):

2. Pain Characteristics

Affected Knee: Onset: Duration (Days/Weeks/Months/Years): Pain Description (Sharp, Dull, Aching, etc.): Pain Severity (0-10): Is the pain constant or intermittent?: What activities worsen the pain?: What treatments help relieve the pain?:

3. Mechanical Symptoms

Knee Swelling Clicking, Popping, or Locking Knee Giving Way or Feeling Unstable Inability to Fully Straighten or Bend the Knee

4. Functional Impact

Limits Daily Activities Unable to Bear Weight Requires Assistance to Walk (e.g., cane, crutches) Affects Sleep or Mental Well-being

5. Red Flag Symptoms

Fever, Chills, or Feeling Unwell Knee Redness, Heat, or Significant Swelling Sudden Swelling Without Injury Unable to Bear Weight Due to Pain

6. Self-Examination Maneuvers

Straight Leg Test: Sit or lie down and try to lift your leg straight while keeping your knee straight. Describe any pain: Bend Test: Stand or sit and slowly bend your knee as far as possible. Describe pain or stiffness: Pressure Test: Press around the knee (front, sides, back). Note any tenderness:

7. Previous Treatments & Medications

Rest, Ice, Compression, Elevation Over-the-Counter Pain Medications Physical Therapy Bracing or Injections

8. Patient Concerns & Expectations

Biggest Concerns About Your Knee Pain: History of Osteoarthritis or Similar Episodes: What Do You Hope to Achieve from This Consultation?:

In summary, knee pain remains a prevalent complaint in the adult population presented to primary care physicians. With a multifactorial nature, underlying causes predominantly include osteoarthritis and previous injuries alongside psychological factors affecting pain perception. Addressing the growing burden of knee pain will require enhanced awareness and innovative treatment strategies within primary care.

Cause	Key Features/Description	Primary Care Considerations
Osteoarthritis	Degenerative joint disease; pain worsens with activity; common in older adults.	Recommend weight loss, exercise, physical therapy. Use NSAIDs/acetaminophen for pain control. Obtain weight-bearing X-rays for assessment.
Rheumatoid Arthritis	Autoimmune inflammatory disorder; symmetrical joint involvement, swelling, warmth, morning stiffness.	Labs: ESR(↑), CRP(↑), Rheumatoid factor, Anti-CCP. Coordinate with rheumatology for DMARD therapy. Address comorbidities and monitor for systemic manifestations.
Meniscal Tears	Injury to knee cartilage (often twisting motion). Symptoms include locking, catching, joint line tenderness.	Perform McMurray’s test. Consider MRI if mechanical symptoms persist. Conservative management first (rest, NSAIDs, PT) before surgical referral.
Ligament Injuries	ACL, PCL, MCL, or LCL damage from pivoting/trauma. Presents with instability, swelling.	Assess with Lachman, drawer, varus/valgus stress tests. MRI if suspicion is high. Refer for severe tears or instability.
Patellofemoral Pain Syndrome	“Runner’s knee.” Anterior knee pain worsened by stair climbing, prolonged sitting, malalignment.	Focus on quadriceps strengthening and activity modification. Assess patellar tracking and foot alignment. Consider physical therapy if persistent.
Patellar Tendinitis	“Jumper’s knee.” Overuse inflammation of patellar tendon, localized below kneecap.	Recommend rest, ice, activity modification. Physical therapy with eccentric quadriceps exercises. NSAIDs for pain and inflammation.
Bursitis	Inflammation of fluid-filled sacs (prepatellar, pes anserine). Localized swelling, tenderness.	Common with overuse or prolonged kneeling. NSAIDs, rest, aspiration if large effusion. Check for infection if redness or warmth is present.
Gout / Pseudogout	Crystal-induced arthropathies; acute severe pain, swelling, redness. Gout (urate↑), Pseudogout (CPPD crystals).	Joint aspiration for definitive diagnosis (monosodium urate vs. CPP crystals). Acute management with NSAIDs, colchicine, or steroids. Long-term management (gout) may require urate-lowering therapy.
Septic Arthritis	Infection within the joint. Severe pain, redness, swelling, fever, inability to bear weight.	Labs: ESR(↑), CRP(↑). Urgent joint aspiration for Gram stain, culture. Rapid antibiotic treatment and orthopedic consult.
Referred Pain	Pain originating from hip or lumbar spine pathology but felt in the knee.	Perform a thorough hip and spine exam. Knee imaging may be normal. Consider imaging of the hip or spine when clinical suspicion is high.

Knee Pain in Adults - Remote triage