Knee Pain Differential Diagnoses

Classification by Anatomical Location

Anterior Knee Pain

• Trastornos patelofemorales, such as cartilage loss, subluxation/dislocation, and friction syndrome, are the most common causes of anterior knee pain, according to the American College of Radiology 1
• Enfermedad de Hoffa, characterized by synovitis with a thickness of more than 2mm in the Hoffa fat pad, is correlated with peripatellar pain, as reported by the Journal of the American College of Radiology 2, 1
• Bursitis infrapatelar profunda can cause anterior knee pain, as stated by Praxis Medical Insights 1
• Plica medial is a cause of anterior knee pain, according to the Journal of the American College of Radiology and Praxis Medical Insights 2, 1
• Osteocondritis disecante can manifest with anterior knee pain, as reported by Praxis Medical Insights 1
• Síndrome de pinzamiento del cuerpo adiposo contributes to peripatellar pain, according to Praxis Medical Insights 1

Medial Knee Pain

• Osteoartritis del compartimento medial is the most common cause of medial knee pain, as stated by Praxis Medical Insights 1
• Fracturas por insuficiencia subcondral, previously known as spontaneous osteonecrosis, frequently affect the medial femoral condyle in middle-aged to elderly women, according to Praxis Medical Insights 1

Lateral Knee Pain

• Síndrome de la banda iliotibial is a frequent cause of lateral knee pain, as reported by the Journal of the American College of Radiology and Praxis Medical Insights 2, 1
• Osteoartritis del compartimento lateral can cause lateral knee pain, according to Praxis Medical Insights 1, 3

Posterior Knee Pain

• Quistes poplíteos (de Baker) cause posterior knee pain and frequently communicate with the joint, as stated by Praxis Medical Insights 1, 3
• Tendinopatía de isquiotibiales can manifest with posterior knee pain, according to Praxis Medical Insights 1

Critical Structural Pathologies

Traumatic and Degenerative Lesions

• Fracturas por estrés tibial can occur in the knee, as reported by Praxis Medical Insights 1
• Cuerpos libres can cause mechanical symptoms, according to the Journal of the American College of Radiology and Praxis Medical Insights 2, 1

Inflammatory and Proliferative Conditions

• Sinovitis villonodular pigmentada is a rare condition that causes pain and swelling, as reported by the Journal of the American College of Radiology and Praxis Medical Insights 2, 1
• Sinovitis/derrame articular can indicate the origin of pain, according to Praxis Medical Insights 1
• Capsulitis adhesiva can cause pain and stiffness, as stated by the Journal of the American College of Radiology and Praxis Medical Insights 2, 1

Specific Bone Lesions

• Osteofitos are signs of osteoartritis, according to the Journal of the American College of Radiology and Praxis Medical Insights 2, 1
• Menisco discoide is a rare condition, as reported by Praxis Medical Insights 1
• Tumores y quistes ganglionares can cause pain and swelling, according to Praxis Medical Insights 1

Critical Differential Diagnosis: Referred Pain

• El dolor referido de la cadera o columna lumbar debe descartarse antes de atribuir los síntomas exclusivamente a patología de rodilla, as stated by Praxis Medical Insights 1, 3
• Patología de columna lumbar debe considerarse cuando las radiografías de rodilla son normales y existe evidencia clínica de origen espinal, according to Praxis Medical Insights 1, 4, 3
• Patología de cadera comúnmente refiere dolor a la rodilla y debe evaluarse si la imagenología de rodilla es normal, as reported by Praxis Medical Insights 1, 4, 3

Specific Conditions by Age Group

Adults Over 70 Years Old

• En pacientes >70 años, pueden existir anormalidades estructurales bilaterales con síntomas predominantemente unilaterales, as stated by Praxis Medical Insights 1

Systemic Inflammatory and Infectious Conditions

• Artropatía periférica tipo I asociada a enfermedad inflamatoria intestinal is pauciarticular, affects large joints (including knees), and correlates with disease activity, according to the Journal of Crohn's and Colitis 5
• Artropatía axial (sacroileítis, espondilitis) can coexist with knee pain in patients with inflammatory bowel disease, as reported by the Journal of Crohn's and Colitis 5

Common Diagnostic Errors to Avoid

• No pasar por alto el dolor referido de cadera o columna lumbar antes de atribuir síntomas exclusivamente a patología de rodilla, as stated by Praxis Medical Insights 1, 3
• Evitar resonancia magnética prematura: aproximadamente 20% de pacientes con dolor crónico de rodilla reciben resonancia sin radiografías recientes, according to Praxis Medical Insights 1, 3

Evidence-Based Diagnostic Algorithm

Initial Evaluation

• Obtener radiografías anteroposterior y lateral de rodilla primero para excluir fracturas, osteoartritis, osteofitos y cuerpos libres, as recommended by Praxis Medical Insights 3

Advanced Imaging

• Si las radiografías son normales o muestran solo derrame pero el dolor persiste, resonancia magnética sin contraste intravenoso está indicada, according to Praxis Medical Insights 3
• La resonancia magnética es excelente para identificar desgarros meniscales, lesiones ligamentosas, edema de médula ósea y quistes de Baker, as reported by Praxis Medical Insights 3
• Considerar radiografías de cadera si el examen e imagenología de rodilla no son reveladores, as recommended by Praxis Medical Insights 3